MOSCOW (Reuters) -Russia is considering a possible downgrading of relations with the West due to the deeper involvement of the United States and its allies in the Ukraine war, but no decision had yet been taken, the Kremlin said on Thursday.

A downgrading of relations - or even breaking them off - would illustrate the gravity of the confrontation between Russia and the West over Ukraine after an escalation in tensions over the war in recent months.

Even during the 1962 Cuban Missile Crisis, when the Cold War is thought to have come closest to nuclear war, Russia did not sever relations with the United States, though Moscow did break off ties with Israel over the 1967 Middle East war.

Russian Deputy Foreign Minister Sergei Ryabkov told the Izvestia newspaper that ambassadors fulfilled a difficult but important job that allowed a channel of communication to operate in troubled times.

But Ryabkov also said that a possible downgrading of ties with the West was being studied.

When asked about the possibility of such a move, Kremlin spokesman Dmitry Peskov said that given the West's current approach to Russia it was one of several options that was being considered, though no decision had yet been made.

"The issue of lowering the level of diplomatic relations is a standard practice for states that face unfriendly or hostile manifestations," Kremlin spokesman Dmitry Peskov said.

"Due to the growing involvement of the West in the conflict over Ukraine, the Russian Federation cannot but consider various options for responding to such hostile Western intervention in the Ukrainian crisis."

President Vladimir Putin, who ordered thousands of troops into Ukraine in 2022, presents the war as part of a wider struggle with the U.S., which he says ignored Moscow's interests after the 1991 collapse of the Soviet Union and then plotted to split Russia apart and seize its natural resources.

The West and Ukraine have cast the war as an imperial-style land-grab. Western leaders, who deny they want to destroy Russia, say that if Putin wins the war then autocracies across the world will be emboldened.

With Russia gaining the upper hand in the biggest land war in Europe since World War Two, the Ukraine crisis has escalated in recent months.

After the United States allowed Ukraine to strike Russia with some U.S. weapons, the Kremlin sent signals that it viewed this as a serious escalation.

Putin has ordered drills to practise deployment of tactical nuclear weapons, suggested Russia could station conventional missiles within striking distance of the United States and its allies, and sealed a mutual defence pact with North Korea.

The United States and its European allies still have embassies in Russia, and Russia has embassies in Washington and European capitals, though diplomats from both sides say they are experiencing the most hostile conditions in decades.

"Moscow has given up on repairing relations with the West," said Geoffrey Roberts, a historian of Josef Stalin and Soviet international relations at University College Cork.

"It would signal that Putin thinks he can usher in a Brave New Multipolar World, whilst at the same time keeping the West at arm's length," he said. "But maybe its a just a gesture, a protest, a sign of frustration with the West and/or a sop to Russian hardliners who want to escalate the war in Ukraine."

(Reporting by FaulconbridgeEditing by Andrew Osborn and Andrew Heavens)

By Guy Faulconbridge