Former President Donald J. Trump repeated familiar boasts and grievances in a keynote speech at the Conservative Political Action Conference on Saturday.

Mr. Trump repeatedly invoked the lie that the 2020 election was “rigged” and mounted exaggerated attacks on President Biden. Even as he condemned Russia’s invasion of Ukraine as an “atrocity” and praised the country’s president, Volodymyr Zelensky, as a “brave man,” he repeated his misleading claim that the Obama administration had merely provided Ukraine with “blankets.”

Here’s a fact-check.

What Mr. Trump Said

False. During his campaign in 2016, Mr. Trump promised to construct a 1,000-mile-long border wall that would be paid for by Mexico. By the time he left office, his administration had constructed 453 miles of border wall, most of which replaced or reinforced existing barriers. In places where no barriers previously existed, the administration built a total of 47 miles of new primary wall.

Mr. Trump’s vow that he would have been able to complete the wall within three weeks also does not track with the initial construction pace. Construction of replacement barriers in Calexico, Calif., began in February 2018, the first border wall project under Mr. Trump. Construction of the first new section of wall in the Rio Grande Valley began in November 2019. That amounts to 12.9 miles of replacement wall and 3.3 miles of new wall per month.

What Mr. Trump Said

False. When Mr. Trump left office in January 2021, the national average price of a gallon of gasoline for that month was $2.42. That is not a record low. Gas prices fell to $2.21 in January 2015 under former President Barack Obama, $1.13 under former President George W. Bush and $0.96 under former President Bill Clinton.

What Mr. Trump Said

This is misleading. Mr. Trump was referring to the status of a natural gas pipeline between Russia and Germany under his administration and that of President Biden. In fact, American presidents — and most European countries other than Germany and France — have consistently opposed the project, but they have limited say in whether the pipeline is built.

Mr. Trump signed a law imposing sanctions on the Nord Stream 2 pipeline in December 2019, prompting a suspension in construction. But by then, most of the pipeline had already been built, with 2,100 kilometers laid and 300 kilometers remaining. Construction resumed a year later in 2020.

The current White House press secretary, Jen Psaki, described Nord Stream 2 as a “bad deal” that divides Europe and leaves Ukraine and Central Europe vulnerable to Russian manipulation. Secretary of State Antony Blinken said that the Biden administration’s opposition was “unwavering.”

But the State Department nonetheless lifted sanctions on the company building the pipeline in May 2021. According to the nonpartisan Congressional Research Service, this might be because “the administration’s ability to prevent the pipeline from becoming operational is limited” while sanctions “could jeopardize U.S.-German and U.S.-European cooperation in other areas, including countering Russian aggression.”

Mr. Biden issued new sanctions on the pipeline this week after Germany announced that it would suspend the certification of the pipeline in response to Russia’s invasion of Ukraine.

What Mr. Trump Said

This is misleading. The Biden administration indefinitely halted new federal oil and gas leases and permits in response to a court ruling. It did not revoke existing leases. A federal judge had blocked the way the administration was calculating the cost of climate change, leading the administration to pause regulatory decisions that relied on the metric.