Biden is expected to formally recognize the massacre of Armenians by the Ottoman Empire during World War One as an act of genocide, but the statement made no mention of the issue.
Russia retaliated by ordering out 20 Czech diplomats -- sparking an angry ultimatum from Prague for Moscow to let them return or face further expulsions from its embassy.
"Mr President, as you said last year in your April 24 statement, 'Silence is complicity.' The shameful silence of the United States government on the historic fact of the Armenian Genocide has gone on for too long, and it must end," the letter said.
Russia will soon have more than 120,000 troops on Ukraine's border, Ukrainian Foreign Minister Dmytro Kuleba said on Tuesday, calling for new Western economic sanctions on Moscow.
Kyiv, Washington and NATO have been alarmed by the large build-up of Russian troops near Ukraine and in Crimea, the peninsula that Moscow annexed from Ukraine in 2014.
US President Joe Biden announced Wednesday the unconditional withdrawal of US troops from Afghanistan, naming September 11 as the deadline by which the last soldiers will have finally departed. The pullout will begin on May 1.
India is concerned about a vacuum developing in Afghanistan following the proposed withdrawal of United States and NATO forces from the country, the chief of the defence staff said on Thursday.
General Bipin Rawat told a security conference that the worry was “disruptors” would step into the space created by the withdrawal of foreign troops from Afghanistan.
"This drawdown will be orderly, coordinated, and deliberate. We plan to have the withdrawal of all US and Resolute Support Mission forces completed within a few months," the statement said.
Biden said the United States had "accomplished" its limited original mission of crushing the international militants groups behind the 9/11 attacks and that with every passing year the rationale for staying was "increasingly unclear."
The US secretary of state also met with EU foreign policy chief Josep Borrell, both of whom expressed deep concern over Russian troop movements, according to a European statement.
"President Biden affirmed the United States' unwavering support for Ukraine's sovereignty and territorial integrity in the face of Russia's ongoing aggression in the Donbass and Crimea," the statement said.
"The leaders agreed these reforms are central to Ukraine's Euro-Atlantic aspirations," the statement said.
In remarks to parliament, Khomchak also accused pro-Moscow separatists of systematically violating a ceasefire in the conflict in eastern Ukraine agreed in July 2020.
Ukraine and Russia have traded blame for a spike in violence in the conflict, which Kyiv says has killed 14,000 people since 2014.