United States President Joe Biden was due to meet eastern European leaders on Wednesday, a day after vowing Russia would never see victory in Ukraine.
Vladimir Putin has said Russia will press on with its nearly year-long war. On Tuesday, he accused the West of escalating the conflict and announced Moscow would suspend participation in the New START nuclear arms treaty with Washington.
The Russian president said increasingly stringent sanctions on the country “will not succeed” and vowed his country would keep fighting to “systematically” achieve its aims.
Speaking hours later in the capital of NATO ally Poland, Biden pledged that “Ukraine will never be a victory for Russia — never”.
The 80-year-old leader had a day earlier made a surprise visit to Kyiv, his first since the invasion began and just days before the war’s one-year anniversary.
Surrounded by a flag-waving crowd outside Warsaw’s Royal Castle, Biden responded directly to Putin’s accusations, saying the West “is not plotting to attack Russia”.
He said Putin “thought autocrats like himself were tough” but faced the “iron will” of the United States and its partners.
“There should be no doubt: our support for Ukraine will not waver, NATO will not be divided and we will not tire.”
Biden earlier met Polish President Andrzej Duda, saying his visit had come “at a critical moment”.
He also reaffirmed Washington’s “iron-clad” commitment to NATO’s principle of collective defence.
Duda said that thanks to Biden “we can see that America can keep the world order”.