With diplomatic talks seemingly stalled and the war of words between Washington and Moscow intensifying, President Biden said the United States would be willing to impose personal sanctions against President Vladimir V. Putin of Russia if he directed Russian forces to invade Ukraine.
The threat to target the leader of a world power directly reflected both the Biden administration’s intent to deter Russian aggression by conveying the high costs it would incur, as well as a recognition that Mr. Putin would most likely be the one who decides whether to invade.
Russia has said it has no intention of invading Ukraine, despite amassing forces along the country’s borders to the north, east and south. Mr. Putin has not commented publicly on the crisis since Dec. 23, a silence that has kept Western leaders unsure about his next move.
For weeks, the Biden administration has warned Russia that it would impose punishing economic sanctions if it invades Ukraine. Asked on Tuesday whether those penalties could directly target Mr. Putin, Mr. Biden told reporters at the White House, “Yes, I would see that.”
Mr. Putin’s spokesman, Dmitri S. Peskov, said that threats of direct sanctions against the Russian leadership would not have any serious effect financially or change its course of action.
“It wouldn’t be painful politically, it would be destructive,” Mr. Peskov said on Wednesday.
At a news conference last week, Mr. Biden said he expected that Russia would ultimately invade Ukraine. But he acknowledged on Tuesday how hard it is to read the Russian leader.
“I’ll be completely honest with you: It’s a little bit like reading tea leaves,” he said, according to a White House transcript. “Ordinarily, if it were a different leader — the fact that he continues to build forces along Ukraine’s border from Belarus all the way around — you’d say, ‘Well, that means that he is looking like he’s going to do something.’ But then you look at what his past behavior is and what everyone is saying in his team, as well as everyone else, as to what is likely to happen: It all comes down to his — his decision.”
Britain’s foreign secretary, Liz Truss, signaled on Wednesday that her government would also consider directly targeting Mr. Putin with sanctions. “We’re not ruling anything out,” she told Sky News.
Washington is expected to deliver a written response this week to Russian security demands, but because Moscow has demanded that NATO forces essentially withdraw from Eastern Europe, a request that American officials have described as a nonstarter, it is unclear where the two sides will find room for compromise.
Both Russia and Western nations have stepped up military activity. Russia has held drills near the Ukrainian borders, the United States has placed 8,500 troops on high alert for deployment to Eastern Europe, NATO has increased deployments in the region and some American allies have supplied weapons to the Ukrainian government.
The diplomatic efforts shifted to Paris on Wednesday, where envoys of Russia, Ukraine, Germany and France were expected to meet to set the groundwork for another meeting of the leaders of those nations. President Emmanuel Macron of France said he would speak to Mr. Putin by phone on Friday.
In Ukraine, President Volodymyr Zelensky continued to urge the public to remain calm.
“Protect your body from viruses, your brain from lies, your brain from lies, your heart from panic,” he told the nation in a video message.