U.S. Warns Allies Russia Could Put a Nuclear Weapon Into Orbit This Year

American intelligence agencies have told their closest European allies that if Russia is going to launch a nuclear weapon into orbit, it will probably do so this year — but that it might instead launch a harmless “dummy” warhead into orbit to leave the West guessing about its capabilities.

The assessment came as American intelligence officials conducted a series of rushed, classified briefings for their NATO and Asian allies, as details of the American assessment of Russia’s intentions began to leak out.

The American intelligence agencies are sharply divided in their opinion about what President Vladimir V. Putin is planning, and on Tuesday Mr. Putin rejected the accusation that he intended to place a nuclear weapon in orbit and his defense minister said the intelligence warning was manufactured in an effort to get Congress to authorize more aid for Ukraine.

During a meeting with the defense minister, Sergei K. Shoigu, Mr. Putin said Russia had always been “categorically against” placing nuclear weapons in space, and had respected the 1967 Outer Space Treaty, which prohibits weaponizing space, including the placement of nuclear weapons in orbit.

“We not only call for the observance of the existing agreements that we have in this area,” he was quoted as saying by the Russian state media, “but we have proposed many times to strengthen these joint efforts.”

On Wednesday, Mr. Putin reinforced the central role he believes Russia’s nuclear arsenal plays in the country’s defenses: Visiting an aviation factory, he climbed into the bomb bay of a Tu-160M strategic bomber, the most modern in the Russian fleet.