Hanoi, Vietnam ? Vietnam and the United States tentatively agreed on Wednesday to allow the first commercial flights between the two countries since the end of the Vietnam War, an official said.

The two sides still were working out the final details, but were expected to initial an agreement today, according to an official from Vietnam’s Civil Aviation Administration who poke on condition of anonymity.

Vietnam’s relations with the United States have broadened since a bilateral trade agreement went into effect in December 2001. The pact has significantly increased two-way trade between the former foes, but negotiators have been unable to reach an agreement on air travel.

American carriers now must use code-sharing agreements with other airlines that operate in the country, which means passengers flying between the two countries have to switch planes somewhere before reaching their final destination.

A U.S. Embassy official, also speaking on condition of anonymity, said both sides were expected to meet today for the initialing.

The accord, which would have to be formally accepted by both countries, would allow commercial flights between the United States and Vietnam, but no details were available on when the service would begin.