Russia dispatched two long-range and nuclear-capable aircraft on patrol over Belarus on Saturday, amid escalating tensions over Ukraine.

According to the Russian Defense Ministry, the two Tu-22M3 bombers trained engaging with Belarus’ air force and air defense amid a four-hour flight. The flight followed numerous such patrols over Belarus, which shares borders with Ukraine in the north.

The deployment occurred as the Kremlin transferred soldiers from the Far East and Siberia to Belarus for large-scale joint exercises. The deployment contributed to Russia’s military buildup near Ukraine, increasing Western worries of an invasion.

Russia has denied any preparations to attack Ukraine but has asked the US and its allies to offer a binding guarantee that they would not admit Ukraine to NATO, will not deploy offensive weaponry and will reduce NATO deployments to Eastern Europe. The requests have been rejected by Washington and NATO.

The West has requested  Russia to withdraw an estimated 100,000 soldiers from territories bordering Ukraine, but the Kremlin has replied by declaring that troops would be stationed wherever they are needed on Russian soil. As tensions over Ukraine have risen, Russia’s military has begun a series of war simulations stretching from the Arctic up to the Black Sea.

The deployment of the Russian troops in Belarus sparked fears in the West that Moscow might launch an assault on Ukraine from the north. Kyiv, the Ukrainian capital, lies about 75 kilometers from the Belarus border.

Recent months have seen a series of Russian-Belarus joint drills as well as the deployment of a number of long-range bombers, which are nuclear-capable, to patrol above Belarus.

Belarus’ authoritarian leader, Alexander Lukashenko, has pressed for deeper military relations with Moscow and even volunteered to host Russian nuclear weapons, despite crushing Western sanctions sparked by his assault on domestic protesters.

In an interview that aired Saturday, Lukashenko said that the security alliance led by Russia displayed its swift deployment capacity when its members temporarily dispatched soldiers to Kazakhstan last month to assist control the situation after fatal protests.

“ While they (NATO) will be still getting prepared to send some troops here, we will already stand at the English Channel, and they know it,” he said about Western allies.

The Belarussian president minimized the prospect of war, but said that if it does erupt, “it will last for three or four days at most.”

“There is no one there to fight us,” he remarked of Ukraine.

The German daily Bild released a story on Saturday stating that Russia is preparing to launch a multi-pronged assault on Ukraine, seize key towns, and establish a puppet government. Maria Zakharova, a spokesperson for the Russian Foreign Ministry, scoffed at the charges.

As war concerns grew, Ukrainian officials organized a series of civil defense exercises for people.

“I am here to learn how to defend myself, defend my relatives and also understand how to act in the situation,” a Kyiv resident said. “I am happy that I came here to learn the basics of self-defense and first aid.”

Thousands of people came to the streets Saturday in Kharkiv, Ukraine’s  2nd largest city, roughly 25 kilometers south of the Russian border, holding huge yellow-and-blue banners in a show of commitment to safeguard the city.

“We want to show that there are people in Kharkiv who are ready to defend it and fight back,” marcher Svitlana Galashko stated.

In the midst of the Ukraine crisis, US President Joe Biden has dispatched 2,000 US soldiers to Poland and Germany, as well as 1,000 more soldiers from Germany to Romania, as a demonstration of the US commitment to NATO’s eastern flank.

Earlier this week, Vladimir Putin underlined Moscow’s willingness to have more discussions with Washington and its NATO partners. As part of the high-level diplomacy to defuse tensions, French President Emmanuel Macron will visit Kyiv and Moscow on Monday and Tuesday, while the German Chancellor Olaf Scholz will visit Kyiv and Moscow on February 14-15.

On Saturday, Boris Johnson, the British Prime Minister, spoke with Macron, and “they agreed that finding a diplomatic solution to the current tensions must remain the overriding priority.”

According to Johnson’s office, he and French President Emmanuel Macron “also stressed that NATO must be united in the face of Russian aggression” and “agreed to continue to work together to develop a package of sanctions which would come into force immediately should Russia further invade Ukraine.

 Volodymyr Zelenskyy, Ukrainian President, also talked with Charles Michel, the European Council President, on Saturday, stressing on Twitter that tensions around Ukraine’s position must be de-escalated.

After Ukraine’s Moscow-friendly leader departed the nation in 2014, Russia seized the Crimean Peninsula. Russia has also backed in eastern Ukraine a separatist insurgency, where more than 14,000 people have been murdered in conflict.

In the midst of tensions with the West, Putin attended the Winter Olympics’s opening in Beijing on Friday and met with Xi Jinping to deepen the two nations’ partnership. Putin and Xi issued a joint statement in which they stated their opposition to NATO expansion while asserting the island of Taiwan as a part of China.

Putin and Xi said that Moscow-Beijing ties are “superior to political and military alliances of the Cold War era” and that their friendship “has no limits.”