A US court on Monday issued warrants for the seizure of two luxury planes owned by Russian billionaire Roman Abramovich under US measures imposed after Russia's military operation in Ukraine, court records showed.

But the US government's likelihood of gaining control of the aircraft worth nearly US$400 million was uncertain.

A Department of Justice official said the US$350 million Boeing 787 Dreamliner and US$60 million Gulfstream G650 ER were not in US custody, and the official declined to say if the US government knows their locations.

A federal judge in Manhattan issued the warrants on the grounds that recent flights violated US export controls imposed after Russia's invasion of Ukraine in February. The US Department of Commerce filed related administrative charges against Abramovich.

But the official said the warrants are likely to dissuade companies from helping to move the aircraft. US authorities are seeking to pressure business leaders close to Russian President Vladimir Putin to get him to halt what Kremlin calls its "special military operation" in Ukraine.

A spokesperson for Abramovich did not immediately respond to a request for comment. Abramovich has denied having close ties to Putin.

The Commerce Department said that the Gulfstream flew from Istanbul to Moscow on March 12, left the following day for Tel Aviv and flew from Istanbul to Moscow again on March 15. The Boeing flew from Dubai to Moscow on March 4, the department said.

Because the planes were US-made, and the flights took place after export restrictions went into effect, Abramovich, a Russian national, would have needed a license from Commerce to fly them to Russia. No licenses were requested, but an administration official told reporters the department's policy is to deny such requests. (Reuters)