WASHINGTON -- A senior U.S. general on Wednesday accused Russia of deploying a land-based cruise missile in violation of "the spirit and intent" of a nuclear arms treaty and charged that Moscow's intention is to threaten U.S. facilities in Europe and the NATO alliance.

"We believe that the Russians have deliberately deployed it in order to pose a threat to NATO and to facilities within the NATO area of responsibility," Gen. Paul Selva, vice chairman of the Joint Chiefs of Staff, told a House Armed Services Committee hearing.

Selva said he sees no indication that Moscow intends to return to compliance with the 1987 Intermediate-range Nuclear Forces Treaty, which bans an entire class of weapons -- all land-based cruise missiles with a range between 500 and 5,500 kilometres (310 and 3,410 miles). The treaty was a landmark in arms control in the final years of the Cold War.

Selva's accusation takes on added political significance in light of U.S. President Donald Trump's stated goal of improving relations with Russia, even as Moscow is perceived by U.S. allies in Europe as a military threat of growing urgency. The alleged treaty violation comes amid multiple congressional investigations of alleged Russian interference in the 2016 presidential election. The FBI also is probing ties between Russia and Trump associates during the campaign.

Trump has said little about the INF treaty but on multiple occasions has questioned the value of a separate, more recent treaty that limits the number of strategic nuclear weapons the United States and Russia can deploy to 1,550 warheads each, starting in 2018. Trump has said it unfairly advantages Russia. And he has said the U.S. should expand its nuclear weapons capability, although he has not explained what he meant.

Even before Trump's election, the Pentagon was weighing implications of a shift in Russian nuclear doctrine that seems to lower the threshold for the combat use of nuclear weapons. The Russians have framed their new thinking as "escalate, to de-escalate," meaning possibly using a small number of nuclear weapons to persuade an opponent not to escalate the conflict and possibly lead to all-out nuclear war.

"We have to account ... for what that means," Selva said Wednesday.

"We've begun an investigation of a series of potential strategy changes," he said, in part by conducting war games and military exercises.

The Obama administration had hoped to talk Moscow into returning to compliance with the INF treaty but seemed to make no progress. Russia has claimed U.S. missile defences violate the threat. Asked how the U.S. might respond now that Russian cruise missiles are deployed for potential use, Selva said the military is preparing a set of options to be considered this year by the Trump administration as part of a broader nuclear policy review.

Selva said he could not publicly discuss those options. When pressed he said the plan is to "look for leverage points to attempt to get the Russians to come back into compliance," adding, "I don't know what those leverage points are."

The Obama administration had accused Moscow of violating the INF treaty, but Selva's statement was the first public confirmation of recent news reports that the Russians have deployed the nuclear-capable cruise missile.

The New York Times, which was first to report the Russian missile deployment, said last month that the Russians have two battalions now in the field. One is at a missile test site at Kapustin Yar and one was moved in December from the test site to an operational base elsewhere in the country. Russia denies that it has violated the INF treaty.

Some in Congress have expressed alarm at the alleged Russian deployment. Sen. John McCain, the Senate Armed Services Committee chairman, last month called on the Trump administration to ensure that U.S. nuclear forces in Europe are ready.

"Russia's deployment of nuclear-tipped ground-launched cruise missiles in violation of the INF treaty is a significant military threat to U.S. forces in Europe and our NATO allies," McCain, R-Ariz., said, adding that he believes Russian President Vladimir Putin was "testing" Trump.

In response to questions at the hearing on Wednesday, Selva said U.S. officials have been talking to Moscow about the alleged treaty violation. He seemed unconvinced that the discussions would be fruitful.

"I don't have enough information on their intent to conclude other than they do not intend to return to compliance" with the treaty, he said. "Absent some pressure from the international community and the United States as a co-signer of the same agreement," there is no logical reason to believe that Moscow intends to end its violations, he added.