Lithuanian President Gitanas Nauseda arrives at a European Union leaders last-minute summit to discuss the crisis between Ukraine and Russia, in Brussels, Belgium February 24, 2022.
Lithuanian President Gitanas Nauseda arrives at a European Union leaders last-minute summit to discuss the crisis between Ukraine and Russia, in Brussels, Belgium February 24, 2022. Reuters / YVES HERMAN

U.S. Secretary of State Antony Blinken on Monday sought to reassure Washington's Baltic allies on a visit to the region, where he heard concerns that Russian President Vladimir Putin could go beyond his invasion of Ukraine in redrawing the borders of Europe.

Blinken spent the weekend in Ukraine's neighbours Poland and Moldova before visiting Lithuania, Latvia and Estonia, NATO members that were once ruled from Moscow and fear they could face Russian aggression next.

Addressing Blinken, Lithuanian President Gitanas Nauseda warned that Putin "will not stop in Ukraine" and that the world had an obligation to help Ukrainians "by all means available" to avoid a third World War.

"Deterrence is no longer enough and we need forward defence here in place because otherwise it will be too late here, Mr Secretary. Putin will not stop in Ukraine if he will not be stopped," Nauseda said.

Russia calls the campaign it launched on Feb. 24 a "special operation" that it says is not designed to occupy territory but to destroy its neighbour's military capabilities and capture what it regards as dangerous nationalists. Russia denies deliberately targeting civilians.

He met Latvia's foreign minister on Monday ahead of meetings with Prime Minister Krisjanis Karins and President Egils Levits.

Before departing Vilnius for Riga, he said NATO was continuously reviewing its defence posture, including by looking at more permanent deployments, as Baltic countries have requested.

"No one should doubt our readiness, no one should doubt our resolve," Blinken said.

The U.S. commitment to NATO's Article 5 guarantee of mutual defence between member states was "sacrosanct", Blinken added.

NATO countries have ramped up their presence in the Baltic nations and more troops and equipment are on the way, policy makers have announced. Some 400 U.S. troops from the First Armored Brigade Combat Team would be arriving in Lithuania in the coming days, Blinken said.

He said Moscow had sought to undermine Lithuania's democracy and sow polarisation within its population with cyber attacks and disinformation campaigns.

"That's because the free, open, vibrant and prosperous society the people of Lithuanian have built since the end of Soviet occupation, shows what's possible when people choose the path of democracy over autocracy," Blinken said.

Lithuania also joined Ukrainian President Volodymyr Zelenskiy in calling for an embargo on Russian energy on Monday. Blinken said on Sunday the United States and European allies were exploring banning imports of Russian oil.

"Energy sources which we import pay for the Russian military operation. We cannot pay for oil and gas with the blood of Ukraine," Lithuanian Foreign Minister Gabrielius Landsbergis told a joint news conference with Blinken.

Russian gas cannot be easily replaced, however. Norway, Europe's second largest supplier, is already operating at maximum capacity, and Europe's existing LNG terminals have limited available capacity to absorb extra supply.

Blinken earlier told staff of the U.S. Embassy in Vilnius that Russia's invasion of Ukraine challenged basic principles designed to keep the peace between nations.

"It's important that people understand what's actually at stake and it goes beyond even Ukraine, beyond even the Baltic countries, beyond even Europe," Blinken said.