BRUSSELS — President Biden caused controversy in his news conference Wednesday night by stating the obvious: that the many European allies of the United States are not all in agreement at this point about what to do should Russia choose any number of aggressive options toward Ukraine.

“It’s very important that we keep everyone in NATO on the same page,” Mr. Biden said. “That’s what I’m spending a lot of time doing. There are differences. There are differences in NATO as to what countries are willing to do, depending on what happened, the degree to which they’re able to go.”

But the European view has always been divided about what to do and in what circumstances to do it. As one senior European official said, the punishment must fit the crime. He noted that even after Russia annexed Crimea, it took nearly a year for the European Union to respond with serious sanctions against Moscow, and then mostly driven by the shooting down of a civilian airliner, MH17, by Russian-backed separatists in Ukraine in July 2014.

Europeans and NATO are united with the United States in opposing any further Russian incursion into Ukraine, in pledging support of varying kinds for Ukraine, and in promising “massive costs” to Russia — while leaving the extent of those costs unspecified, and for obvious reasons, which Mr. Biden himself described Wednesday night.

Mr. Biden also created confusion when he suggested that a “minor incursion” by Russian forces, as opposed to a full-scale invasion, might not prompt the severe response Washington and its allies have threatened.

The White House later tried to clarify his words, saying that what Mr. Biden meant to say was that any further move of Russian forces into Ukraine would qualify as an invasion.

Ulrich Speck of the German Marshall Fund in Berlin said that Mr. Biden was using the kind of language allies speak to one another. “But that’s not the way you talk to the Russians, because when you talk to the press you talk to the Russians,” he said. “If the point is to reinforce allied unity, this was an unforced error.”

At the same time, he said, the allies were coming together more strongly and more quickly than in 2014, and a NATO of 30 countries and a European Union of 27 “is never perfectly united, we’re not an autocracy, there are always differences and in the open.’’

But there was considerable unity “demonstrated in the language of the alliance,” he said. Mr. Biden’s comments perhaps “should not have happened, but they won’t undermine the Western position.”

The European Union considers that its main strength is in economic sanctions, and those are an active subject of intense and secret discussions, senior European officials say. Tough sanctions will come if Russia does not respond to diplomacy, but inevitably they will be calibrated to what Russia actually does.

All agree they should be punishing and severe, but some countries are more wary than others, and all know that such measures will hurt the European economy far more than the American one. That is especially true given high energy prices and the fact that Europe still gets 40 percent of its natural gas and 25 percent of its oil from Russia.

Yet the divisions run across Europe and within countries themselves. In Germany, the new coalition government is split over what to do with Nord Stream 2, the much-criticized new natural-gas pipeline that runs directly from Russia to Germany, bypassing Ukraine and Poland and thus denying them transit fees.

Foreign Minister Annalena Baerbock, from the Greens, has been far more critical of the pipeline than prominent members of the Social Democratic Party, including the defense minister, Christine Lambrecht, who last week warned against drawing a link between the pipeline and the crisis threatening Ukraine.

“We should not drag it into this conflict,” Ms. Lambrecht told the broadcaster RBB. “We need to solve this conflict, and we need to solve it in talks — that’s the opportunity that we have at the moment, and we should use it rather than draw a link to projects that have no connection to this conflict.”

Her party leader and chancellor, Olaf Scholz, has been more circumspect, saying after a meeting with the NATO secretary-general, Jens Stoltenberg, on Tuesday that Germany was ready to discuss halting the pipeline should Russia attack Ukraine. “It is clear that there will be a high price to pay and that everything will have to be discussed should there be a military intervention in Ukraine,” Mr. Scholz said.

The issue is sensitive for Washington, too. Last week, at NATO, Wendy R. Sherman, the deputy secretary of state, said: “From our perspective, it’s very hard to see gas flowing through the pipeline or for it to become operational if Russia renews its aggression on Ukraine.”

But the divisions are precisely why her boss, the secretary of state, Antony J. Blinken, is in Berlin on Thursday to talk to the German government and to senior diplomats from Britain and the so-called Normandy Format on Ukraine — France and Germany.

Set up in 2014 after the commemoration of D-Day in Normandy, the group includes Russia, Ukraine, France and Germany, but not the United States, because at the time President Barack Obama wanted to leave Ukraine to the Europeans.

Some consider that to have been a mistake, and there are discussions now about whether the United States should also join to try to de-escalate the current crisis. Negotiations produced the Minsk accords, which both Russia and Ukraine accuse the other of violating, and which Russia continues to say hold the key to the Ukrainian crisis.

Further divisions were on display on Wednesday in Strasbourg, France, where Emmanuel Macron, the French president, gave a long speech to the European Parliament setting out his priorities for the French presidency of the European Union — and implicitly for his own re-election campaign with voting in April.

Mr. Macron called on Europeans to come up with their own proposals on European security, “share” them with NATO and “conduct their own dialogue” with Russia.

“These next few weeks should lead us to bring to fruition a European proposal building a new order of security and stability,” he said. “We must build it between Europeans, then share it with our allies within the framework of NATO. And then propose it for negotiation to Russia.”

That proposal surprised and annoyed many of his European Union colleagues, who had not been briefed in advance.

Nonetheless, Mr. Macron’s call echoed an earlier one by the E.U. foreign policy chief, Josep Borrell Fontelles, to European foreign ministers when he said that “we must be at the table” in the U.S.-Russia talks and that “our main goal should be to ensure E.U. involvement in the process.” He said that he favors separate European proposals on security and has “initiated a discrete direct conversation” with the Russian foreign minister, Sergey V. Lavrov.

French officials emphasized on Thursday that Mr. Macron had said that Europeans should talk among themselves, then talk to NATO before talking to Russia. They argued that he was not trying to break with trans-Atlantic solidarity but continuing his traditional campaign for Europe to develop “strategic autonomy” and the ability to define and defend its own interests.

French officials also pointed out that France had volunteered on Wednesday to send enhanced military support to its NATO ally Romania on the southern flank of the alliance, if NATO decided to do that in response to the Ukraine crisis, much like NATO’s forces in Poland and the Baltic countries.

After the Macron speech, Mr. Borrell spoke to both Mr. Blinken and Mr. Stoltenberg and agreed on the need for “a strong, clear and united trans-Atlantic front,” according to a Borrell news release. The European Union has agreed “to further strengthen coordination with the United States and with NATO,” Mr. Borrell said, and he invited Mr. Blinken to attend a meeting of E.U. foreign ministers on Monday to discuss the Ukraine crisis.

Mr. Stoltenberg then said in a separate statement that the call was a “strong signal of unity,” repeating Mr. Blinken’s plea on Wednesday to avoid “divisions between and within our countries.” But those divisions have always existed.

“Macron reflects what Borrell already said, that the E.U. needs to be at the table of the European security order, especially if things would be changing,” a senior European official said. “So it’s not strange to raise your hand and say we want to be part and parcel of that wider discussion.’’

But Central and Eastern European members trust only Washington and NATO to defend them and deter Russia, not Paris or Berlin or Brussels. The United States, Turkey and Britain have stood out for supplying or agreeing to supply anti-tank missiles, armed drones, naval warships and other weapons, along with money to help Ukraine build its defenses. Others, like the Germans, are reluctant to provide weapons to Ukraine.

A senior French diplomat admitted as much recently. “Obviously, there are very different sensitivities when it comes to Russia within the E.U. and on the European continent,” he said.

But there is “a new European assertiveness and willingness to take into account” that the world and region are “more dangerous and volatile,” he said, adding, “We need to take care of ourselves.” Still, producing real strategic weight in support of these ambitions is a long way off, despite the rhetoric.