MOSCOW (AP) — The Kremlin voiced concern Thursday about what it described as belligerent rhetoric of the Ukrainian leadership, saying it raises concerns about a possible escalation of fighting in a separatist conflict in eastern Ukraine.

Ukrainian and Western officials have worried about a Russian troop buildup near Ukraine, fearing it could herald an invasion. But Moscow has insisted it has no such intention and accused Ukraine and its Western backers of making up the claims to cover up their own allegedly aggressive designs.

Kremlin spokesman Dmitry Peskov said Thursday that “the Ukrainian authorities' aggressive and increasingly intensive provocative action on the line of contact” gives grounds for concerns about a possible flare-up of hostilities.

He said that recent statements from Ukrainian President Volodymyr Zelenskyy and other Ukrainian officials indicate that “the Ukrainian leadership doesn't exclude a forceful scenario.”

“The probability of hostilities in Ukraine still remains high,” Peskov said in a conference call with reporters.

Ukrainian officials have denied an intention to reclaim the rebel regions by force.

The two ex-Soviet neighbors have remained locked in a tense tug-of-war after Russia annexed Ukraine’s Crimean Peninsula in 2014 following the ouster of the country’s Kremlin-friendly president and threw its weight behind a separatist insurgency in Ukraine’s eastern industrial heartland, known as the Donbas. More than 14,000 people have died in the fighting.

President Vladimir Putin has warned NATO against deploying its troops and weapons to Ukraine, saying it represented a red line for Russia and would trigger a strong response. He said Wednesday that Moscow would seek Western guarantees precluding any further NATO expansion and deployment of its weapons near Russia's borders.

U.S. Secretary of State Antony Blinken has warned that Putin could quickly order an invasion of Ukraine and said that Washington stands ready to inflict heavy sanctions on Russia if he does.

Blinken was speaking Wednesday in Riga, Latvia, where he met with his NATO counterparts. He is scheduled to meet Thursday with Russian Foreign Minister Sergey Lavrov on the sidelines of a ministerial meeting of the Organization for Security and Cooperation in Europe in Stockholm.