U.S. President Joe Biden has reiterated "unwavering support" for Kyiv as Russia and Ukraine both launched military exercises near their border amid rising tensions between the two neighbors.
The November 24 events follow reports of a large Russian military buildup near the Ukrainian border that raised fears of a possible invasion.
In a November 24 statement honoring the millions of Ukrainians who died in the Holodomor famine of the 1930s, Biden said that the United States "reaffirms our commitment to the people of Ukraine today and our unwavering support for the sovereignty and territorial integrity of Ukraine."
SEE ALSO: 'A Gift To Posterity': Four Men Who Risked The Wrath Of Stalin To Photograph The HolodomorRussia seized Ukraine’s Crimean Peninsula in March 2014 and has been backing separatists in eastern Ukraine in an ongoing conflict that has claimed more than 13,200 lives since April 2014.
Kyiv and its Western backers have raised alarm bells in recent weeks over a Russian military buildup near Ukraine, whose military intelligence chief claimed on November 21 that Russia has amassed 92,000 troops near its borders and was readying an attack for early February.
Moscow has called such allegations “groundless.”
Russia staged military drills in the Black Sea, south of Ukraine, saying it needed to sharpen the combat-readiness of its conventional and nuclear forces because of what Defense Minister Sergei Shoigu called "the growing activity of NATO countries near Russia's borders."
During the drills, Russian warplanes and ships practiced repelling air attacks on naval bases and responding with air strikes, Interfax reported.
Ukraine, meanwhile, launched exercises of its own near its northern frontier, which it said were meant to beef up preparedness for a potential spillover of a monthslong migrant crisis on the border between European Union member Poland and Belarus.
Russian President Vladimir Putin on November 24 told European Council President Charles Michel that he was concerned by Ukraine's "provocations" to inflate tensions in eastern Ukraine, the Kremlin said.
Putin "expressed concern in connection with continuing provocations of the Ukrainian side aimed at exacerbating the situation on the line of contact," it said in a statement.
The previous day, Shoigu complained that U.S. bombers had rehearsed a nuclear strike on Russia, coming too close to the Russian border -- drills the Pentagon said had adhered to international protocols.
Michel confirmed his call with Putin in a tweet and said that the EU “is following closely the military buildup along Russia’s border with Ukraine.”
“Stressed Russia’s responsibility for advancing peaceful settlement in eastern Ukraine,” he wrote in a separate tweet.
SEE ALSO: NATO Chief, Alliance Heavyweights Warn Russia Over Troop Buildup Near UkraineMeanwhile, Estonian Prime Minister Kaja Kallas expressed her Baltic state's shared concern after talks in Paris with French President Emmanual Macron, and she urged the European Union to be "clear on the European side that the price of taking any steps toward Ukraine will be so high that it will act as a deterrent and make Russia reconsider."
She warned it was urgent for the EU and the United States to agree on a common deterrent because a migrant crisis on the EU-Belarus border blamed on Belarusian strongman Alyaksandr Lukashenka, the postelection transition in Berlin, and France's run-up to a presidential election could present a "perfect storm" for Putin to test the West's resolve.
Amid questions about Putin's intentions in the current atmosphere, Reuters quoted sources in U.S. policy circles as suggesting the Russian leader could be angling for a second summit with Biden, who met with the Kremlin leader in Switzerland in June with mutual relations reportedly at their worst since the Cold War.
The United States and NATO have reaffirmed their support for Ukraine including through warship maneuvers this month in the Black Sea and a delivery of U.S. patrol boats to the Ukrainian Navy.
Ukraine's Border Guard Service, meanwhile, held what it called a "special operation" at the border with Belarus on November 24, including drone exercises and military drills for anti-tank and airborne units amid concerns that a migrant crisis at the Polish-Belarusian frontier could spill into Ukrainian territory.
The service said in a statement that the operation is part of measures to "increase the protection and defense of the Ukrainian border in order to prevent a migration crisis and combat illegal activities."
The operation was conducted jointly with the National Guard, the National Police, and the Armed Forces, the service said.
Volodymyr Nikiforenko, the deputy head of the Border Guard Service, said the main task of the operation was to prevent illegal migrants from crossing the state border and entering Ukraine.
Kyiv has also voiced worries that the border with Belarus, a close Russian ally, could be used by Russia to stage a military assault.
Ukraine has deployed 8,500 troops and police officers to guard its border with Belarus, aiming to prevent possible attempts by migrants to breach the frontier.
It also said some of its airborne units carried out paratrooper jumps in the southern Mykolayiv region, near the country's main seaport of Odesa and Russian-occupied Crimea.
Amid the rising tensions in the region, the U.S. and Russian top military officers spoke over the phone on November 23.
SEE ALSO: U.S., Russian Military Chiefs Speak On The Phone Amid Heightened Tensions Over UkraineGeneral Valery Gerasimov, chief of the Russian General Staff, and General Mark Milley, chairman of the U.S. Joint Chiefs of Staff, discussed "current questions of international security," Russia’s Defense Ministry said in a statement on November 23.
The U.S. Department of Defense confirmed the call, saying in a statement that Gerasimov and Milley discussed "security-related issues of concern."
The Russian Defense Ministry and the Pentagon did not provide further details.