SEOUL, South Korea — The South Korean government said Monday it was running out of patience over a three-week long walkout by pilots at Asiana Airlines and would be forced to end the strike barring swift progress toward a solution.

The latest attempt to seek a solution to South Korea's worst-ever aviation strike collapsed early Monday. A marathon meeting lasting into the early hours failed to achieve an agreement, said Asiana spokesman Oh Kyung-keun. Negotiators began meeting again later Monday, he said.

The pilots' demands include fewer flying hours, more say in management decisions and a higher retirement age. Both sides have offered concessions, but not enough to end the walkout, now in its 23rd day.

If the government steps in, Asiana's union would have to immediately stop the strike for 30 days — a step used in sectors considered critical to the national economy. Asiana is the country's No. 2 carrier after rival Korean Air. Asiana's international destinations include New York, Los Angeles, Seattle, San Francisco, Bangkok, New Delhi, Tokyo, Frankfurt, Sydney, and Tashkent, Uzbekistan.

The strike has forced Asiana to cancel all its cargo flights, over 1,800 domestic flights and more than 100 international passenger flights during the peak summer travel season.

The airline said Sunday it was canceling a total of 314 international flights for the entire month of August, including service to Frankfurt, on Aug. 15th, its first to Europe so far.