The United States threatened again to take action Wednesday against Japanese airlines if Japan blocks a transfer of slots from Delta Air Lines to FedEx at Narita airport.

"The U.S. government stated that if this issue is not resolved quickly, it would consider denying rights to a Japanese carrier or carriers for some of its current U.S. service," U.S. Transportation Secretary Norman Mineta said in a prepared statement. "We will not hesitate to take action if the rights of U.S. air carriers are violated."

Accordingly, the Transportation Department ordered Japanese airlines to submit their all-cargo schedules for services to the U.S. by Friday.

The statement was issued after Japanese and U.S. officials failed to resolve the issue at a meeting Tuesday in Washington.

In the wake of the Sept. 11 terrorist attacks, Delta Air Lines withdrew most of its service to Japan. As a result, the U.S. airline is hoping to give back slots it had obtained from FedEx in 1998.

On Feb. 25, Japan notified the department of its intention to deny the planned transfer of slots, insisting the slots should be put in a pool for reallocation to other carriers.

The proposed transfer is fully in accord with the 1998 U.S-Japan aviation agreement and with international guidelines, the department said in the statement.

Delta plans to return the slots to the U.S. cargo carrier on March 31.

Japanese carriers are keen to grab a bigger share of takeoff and landing slots at Narita. U.S. airlines currently hold 34 percent of the slots at Narita, though that will fall to one-fifth when the airport's second runway opens in April.