(Reuters) -Russian President Vladimir Putin paid tribute to former Prime Minister Shinzo Abe on Thursday, saying he knew the slain Japanese leader had dreamt of finally concluding a post-World War Two peace treaty.

The White House faces the question of whether its appeasement of Russia has failed to achieve the ceasefire it promised and instead emboldened the Kremlin on the battlefield.

Russia's troop buildup on Ukraine's border raises tensions. Zelenskyy and Trump push for peace talks, but Moscow's refusal to hand over memorandum stalls negotiations.

Trump called Putin 'crazy' over the weekend and said May 27 he's 'playing with fire' as he continues to bombard Ukraine during peace negotiations.

The U.S. president lashed out at the Kremlin on Tuesday as the White House continued to consider increasing sanctions against Russia.

President Donald Trump's willingness to come to the table comes just after he condemned Russia’s recent large-scale strike against Ukraine.

Trump wanted to let everyone know that he is very, very upset with Russian President Vladimir Putin’s continuing campaign of civilian slaughter in Ukraine. Sunday’s outburst wasn’t the first time that the American president publicly asked his counterpart in the Kremlin to behave himself.

The United States wants Russia to agree to a comprehensive 30-day land, air, sea and critical infrastructure ceasefire.

Eastern bloc hits out at US sympathy for Putin’s anti-Nato demands - Exclusive: Backlash from top Eastern European officials after Donald Trump’s special envoy to Ukraine said Moscow’s opposition to N