WASHINGTON, April 13. /TASS/. US President Joe Biden expressed his concerns over the situation at the Russian-Ukrainian border and called on Moscow to "de-escalate tensions" during the Tuesday phone call with his Russian counterpart Vladimir Putin.

"President Biden emphasized the United States’ unwavering commitment to Ukraine’s sovereignty and territorial integrity. The President voiced our concerns over the sudden Russian military build-up in occupied Crimea and on Ukraine’s borders, and called on Russia to de-escalate tensions," the White House said in a written statement.

In recent days, Western states repeatedly expressed their concerns over remarks made by Ukrainian military regarding the increase in Russian military presence near the Ukrainian border.

Kremlin spokesman Dmitry Peskov said earlier that movements of Russian armed forces on Russian territory should not be a concern for other states because it does not threaten them. He also underscored that the situation in Donbass is Ukraine’s internal conflict that Russian forces have never participated in.

The situation in Donbass escalated in late February, with shootouts being registered in the region almost everyday, including with the use of mortars and grenade launchers. Both sides accuse each other of escalation of the situation.