* Russia dismisses U.S. assertion of weapon launch

* Russia says the claim is fake news

* Russia launched a rocket on May 17 that US queried

* Russia opposes strike weapons in low orbit, says Moscow

MOSCOW, May 22 (Reuters) - Russia's top arms control diplomat on Wednesday dismissed as fake news an assertion by the United States that Russia had launched a weapon into low-Earth orbit that was capable of inspecting and attacking other satellites.

The Kremlin has flatly denied assertions by U.S. officials that Moscow is developing a

space-based anti-satellite nuclear weapon

. But on Tuesday, U.S. Space Command said Russia had launched an

anti-satellite weapon

.

The United States pointed a launch earlier this month of a Soyuz rocket from Russia's Plesetsk launch site. Russia's

defence ministry

said the May 17 launch had a spacecraft on board but gave no details what it was for.

U.S. Space Command said the launch was a likely a counterspace weapon capable of attacking other satellites in low Earth orbit.

"I don't think we should respond to any fake news from Washington," Russian Deputy Foreign Minister Sergei Ryabkov was quoted as saying by the Interfax news agency about the U.S. claims.

"The Americans can say whatever they want but our policy does not change from this," said Ryabkov, adding that Moscow had "always consistently opposed the deployment of strike weapons in low-Earth orbit."

President Vladimir Putin and his then defence minister, Sergei Shoigu, denied U.S. assertions in February that Russia was developing a space-based anti-satellite nuclear weapon designed to disrupt everything from military communications to phone-based ride services.

U.S. Space Command said the May launch, which it dates as May 16, included COSMOS 2576, a type of Russian military "inspector" spacecraft that U.S. officials have long said exhibits reckless space behaviour.

U.S. intelligence agencies had been expecting the launch of COSMOS 2576 and informed allies of their assessment of the satellite before its deployment in space, according to a U.S. official familiar with the intelligence. The launch also included civilian satellites deployed to different orbits.

COSMOS 2576, as of Tuesday, has not gone near a U.S. satellite, but space analysts observed it to be in the same orbital ring as USA 314, a bus-sized NRO satellite launched in April 2021.

Ryabkov said that Russia's space programme was developing as planned, including tasks aimed at strengthening defence capability but added that "this is also not news".

He said the United States was wrong to have dismissed Russian proposals on strengthening the security of space activities, including a proposal on developing a treaty on preventing an arms race in space.

(Reporting by Reuters; Writing by Guy Faulconbridge Editing by Andrew Osborn)