PRAGUE (Reuters) - US Defense Secretary Jim Mattis said on Sunday that the United States was in consultation with its European allies on an arms control treaty, as NATO members urge Washington to try to bring Russia back into compliance with the pact rather than quit it.

President Donald Trump said on Oct. 20 that Washington planned to quit the Intermediate-Range Nuclear Forces (INF) treaty which Mikhail Gorbachev, the last Soviet leader, and Ronald Reagan had signed in 1987.

Washington has cited Russia's alleged violation of the treaty as its reason for leaving it, a charge Moscow denies. Russia in turn accuses Washington of breaking the pact.

"We are in consultations with our European counterparts, I was speaking about it the day before with the German defense minister, and so as I said the consultations continue," Mattis told reporters traveling with him to Prague.

He met with his Czech counterpart and Prime Minister Andrej Babis during a short trip to Prague. Babis cautioned against exiting the deal, saying that "it would be good for the superpowers to cooperate."

Andrej Babis also told reporters that relations with Russia "aren't ideal and we're returning to Cold War times."

Mattis said ministers from NATO would be meeting in Brussels in December and at that point he would have some kind of "culminating point."

President Donald Trump, left, and Russian President Vladimir Putin arrive for a meeting at the Presidential Palace in Helsinki, Finland, July 16, 2018. AP Photo/Pablo Martinez Monsivais

European members of NATO urged the United States on Thursday to try to bring Russia back into compliance with a nuclear arms control treaty rather than quit it, diplomats said, seeking to avoid a split in the alliance that Moscow could exploit.

Mattis said he had asked his NATO counterparts after the last summit if they had any ideas on how to bring Russia back into compliance of INF treaty, but so far none had come back to him.

European allies see the INF treaty as a pillar of arms control and, while accepting that Moscow is violating it by developing new weapons, are concerned its collapse could lead to a new arms race with possibly a new generation of US nuclear missiles stationed on the continent.

Heather Conley, a former US State Department official now with the Center for Strategic and International Studies in Washington, said Mattis would receive a range of questions from European allies like when a formal notification would be made and whether it signals a new arms race.

"It just deepens the uncertainty. Our allies do not know where US leadership is going, what it's going to do from the day to day basis," Conley said.

When asked whether he could rule out placing intermediate range missiles on the ground if Washington left the INF treaty, Mattis said: "I never rule things out like that. I also don't rule it in."

"There are a number of ways for us to respond. It does not have to be symmetric, and it'll be in close consultation with allies," he added.

(Reporting by Idrees Ali; editing by Toby Chopra)