WARSAW (AP) -- President Joe Biden is wrapping up his whirlwind, four-day visit to Poland and Ukraine by reassuring eastern flank NATO allies that his administration is highly attuned to the looming threats and other impacts spurred by the grinding Russian invasion of Ukraine.
Before departing Warsaw on Wednesday, Biden will hold talks with leaders from the Bucharest Nine, a collection of nations on the most eastern parts of the NATO alliance that came together in response to Russian President Vladimir Putin's 2014 annexation of Crimea from Ukraine.
As the war in Ukraine drags on, the Bucharest Nine countries' anxieties have remained heightened. Many worry Putin could move to take military action against them next if he's successful in Ukraine. The alliance includes Bulgaria, the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania and Slovakia.
"When Russia invaded, it wasn't just Ukraine being tested. The whole world faced a test for the ages," Biden said in an address from the foot of Warsaw's Royal Castle on Tuesday to mark the somber milestone of the year-old Russian invasion. "Europe was being tested. America was being tested. NATO was being tested. All democracies were being tested."
Putin on Tuesday delivered his own address, in which he lashed out against Ukraine and its Western allies. The Russian president also announced Moscow would suspend its participation in the last remaining U.S.-Russia arms control treaty. The move is expected to have an immediate impact on U.S. visibility into Russian nuclear activities, but the pact was already on life support.
Putin's decision to suspend Russian cooperation with the treaty's nuclear warhead and missile inspections follows Moscow's cancellation late last year of talks that had been intended to salvage an agreement that both sides have accused the other of violating.
Biden met Tuesday in Warsaw with Moldovan President Maia Sandu, who last week claimed Moscow was behind a plot to overthrow her country's government using external saboteurs.
Sandwiched between Ukraine and Romania and one of Europe's poorest countries, the Eastern European nation has had historic ties to Russia but wants to join the 27-nation European Union. Biden in his remarks endorsed Moldova's bid to join the EU.
"I'm proud to stand with you and the freedom-loving people of Moldova," Biden said of Sandu and her country in his Tuesday address.
Since Russia invaded Ukraine nearly a year ago, Moldova, a former Soviet republic of about 2.6 million people, has sought to forge closer ties with its Western partners. Last June, it was granted EU candidate status, the same day as Ukraine.
Sandu spoke out last week about a Russian plot "to overthrow the constitutional order." She spoke out after Ukrainian President Volodymyr Zelenskyy said his country had intercepted plans by Russian secret services to destroy Moldova. Those claims were later confirmed by Moldovan intelligence officials.
Biden's speech on the Ukraine war came one day after he made a surprise visit to Kyiv, a grand gesture of solidarity with Ukraine. The address was part affirmation of Europe's role in helping Ukraine repel Russia's ongoing invasion and part sharply worded warning to Putin that the U.S. won't abide Moscow defeating Ukraine.
The White House has praised several eastern flank countries, including Lithuania, Poland and Romania, over the last year for stepping up efforts to back Ukraine with weapons and economic aid and taking in refugees.
Biden has given particular attention to Poland's efforts. The country is hosting about 1.5 million Ukrainian refugees and has committed $3.8 billion in military and economic assistance to Kyiv.
"The truth of the matter is: The United States needs Poland and NATO as much as NATO needs the United States," Biden said during talks with Polish President Andrzej Duda.