Adds Delta comment, more on FAA order in paragraphs 6-7

By David Shepardson

WASHINGTON, Nov 21 (Reuters) - The U.S. Federal Aviation Administration warned major airlines on Friday of a "potentially hazardous situation" when flying over Venezuela and urged them to exercise caution.

The FAA notice cited the "worsening security situation and heightened military activity in or around Venezuela" and said threats could pose risks for aircraft at all altitudes.

There has been a massive American military buildup in the region in recent months, including the U.S. Navy's largest aircraft carrier, at least eight other warships, and F-35 aircraft.

The administration of U.S. President Donald Trump has bombed boats allegedly carrying drugs that have departed from the shoreline of Venezuela and other Latin American countries.

Direct flights by U.S. passenger or cargo carriers to Venezuela have been suspended since 2019 but some U.S. airlines fly over the country for some South American flights.

American Airlines AAL.O said on Friday it had stopped overflying Venezuela in October. Delta Air Lines DAL.N said it had stopped flying over Venezuela "a while ago." United Airlines UAL.O did not immediately comment.

The order requires U.S. airlines to provide the FAA with at least 72 hours advance notice of planned flights but stopped short of prohibiting flights over the country.

The FAA said since September there has been an increase in Global Navigation Satellite System interference in Venezuela, which in some cases caused lingering effects throughout a flight, as well as "activity associated with increasing Venezuela military readiness."

"Venezuela has conducted multiple military exercises and directed the mass mobilization of thousands of military and reserve forces," the FAA said, adding that at no point had Venezuela expressed an intent to target civil aviation.

The agency said the Venezuelan military possessed advanced fighter aircraft and multiple weapons systems capable of reaching or exceeding civil aircraft operating altitudes, and there was potential low-altitude risk from air defense systems and anti-aircraft artillery.

The FAA said it will continue to monitor the risk environment for U.S. civil aviation operating in the region.

(Reporting by David Shepardson; Editing by Nia Williams)

((David.Shepardson@thomsonreuters.com; 2028988324;))