When the United States and its Western allies declared that Ukraine could strike Russian territory with their weapons, President Vladimir V. Putin began ratcheting up the threats.

He triggered drills in Russia to practice the use of tactical nuclear weapons. He said Moscow would consider changing the doctrine that outlines when it would use its nuclear arsenal. He reminded unnamed NATO countries in Europe of their small territories and dense populations, implying they could be easily obliterated.

And this week, the Russian leader took his threats to another corner of the globe, reviving a Cold War-era mutual defense pact with North Korea and warning that he may arm Kim Jong-un in response to the loosened restrictions on Ukraine’s use of Western arms.

“The Westerners supply weapons to Ukraine and say that ‘we don’t control anything here at all,’” he said Thursday, failing to acknowledge the limits Washington and its allies have placed on Ukraine. “We can also say that we delivered something to someone, and then we have no control over anything. Let them think about that.”

His ominous warnings, at the end of a two-day trip to North Korea and Vietnam, placed Russia and the West in a new round of escalation over Ukraine. They come amid distraction and political uncertainty among Kyiv’s chief backers, with potentially game-changing elections on the horizon in the United States and France.

Beyond using nuclear weapons or causing more destruction on the battlefield in Ukraine, the Russian leader is seeking to prove he can pressure and antagonize the West in other ways and other places.