KYIV, Dec 6 - President Volodymyr Zelenskiy on Monday said his armed forces were capable of fighting off any Russian attack, as the country marked its national army day with a display of U.S. armored vehicles and patrol boats, Reuters reported.

U.S. President Joe Biden has pledged his "unwavering support" to Ukraine in its standoff with Moscow ahead of his talks with Russian President Vladimir Putin on Tuesday to try to defuse the crisis.