(CNN) — United Airlines says its flights will now avoid Russian airspace, even though the country has not yet banned US aircraft from overflights.
Two routes between the US and India -- San Francisco to New Delhi and Newark to Mumbai -- will be canceled for the next few days, United spokesperson Leslie Scott told CNN. The airline is also rerouting flights between Newark and Delhi, along with those between Chicago O'Hare and Delhi.
Delta Air Lines said it is no longer flying through Russian airspace for some Asia-bound flights.
Last month, American Airlines began rerouting flights that operated over Ukraine.
Russia has banned dozens of western countries from operating in its airspace, but it has not yet banned US aircraft, even after the US announced it would block Russian flights in US airspace.
President Joe Biden announced those plans to further isolate Russia, saying during his State of the Union address Tuesday night that the move would add "an additional squeeze on their economy."
The FAA is warning pilots that Russian aircraft flying into US airspace could be intercepted as part of the restrictions instituted in response to the war in Ukraine.
A bulletin to pilots that published on Wednesday said all Russian civilian aircraft -- including those chartered, leased or controlled for "the benefit of a person who is a citizen of the Russian Federation" -- are banned from US airspace starting at 9 p.m. ET Wednesday.
The new notice said aircraft operators "who do not comply with these instructions may be intercepted, and their pilots and other crewmembers detained and interviewed by law enforcement or security personnel."
The US ban on Russian aircraft is in place through May 25 and is in effect regardless of whether an aircraft is registered in Russia. The only exceptions: Russian aircraft that are humanitarian flights operating on a permit from the US government and flights experiencing an in-flight emergency.