The White House said on Monday that US President Donald Trump is open to conducting joint strikes with Russia on Islamic State (IS) terrorists.
"I think if there's a way that we can combat ISIS (IS) with any country, whether it's Russia or anyone else, and we have a shared national interest in that, sure we'll take it," Xinhua news agency quoted White House spokesman Sean Spicer as saying at a briefing.
The stance breaks from the policy of the previous US administration, which only worked with Russia to de-conflict air strikes in Syria.
The remark came after the Russian Defence Ministry claimed that two jets from the US-led coalition participated in a strike on IS targets alongside Russian aircraft. But the Pentagon on Monday denied the claim.
"The Department of Defence (DoD) is not coordinating air strikes with the Russian military in Syria," Eric Pahon, a Pentagon spokesman, said.
"DoD maintains a channel of communication with the Russian military focused solely on ensuring the safety of aircrews and de-confliction of coalition and Russian operations in Syria," Pahon added.