British Airways says it was forced to cancel "nearly 100 per cent" of flights for Monday and Tuesday after the British pilots union went ahead with a strike.
The strike was called for by the British Airline Pilots Association (BALPA) amid a heated dispute over pay with the airline.
BALPA said Sunday on Twitter that it put forward a proposal to the carrier's management Wednesday, but had yet to receive a reply.
British Airways said in a statement posted Monday it remains "ready and willing to return to talks with BALPA."
The airline said it was forced to cancel so many flights because "with no detail from BALPA on which pilots would strike, we had no way of predicting how many would come to work or which aircraft they are qualified to fly."
Customers who had flights booked for Monday and Tuesday will likely "not be able to travel as planned," British Airways said. The airline also advised customers not to go to the airport.
Members of the pilots union voted 93% in favor of a strike in July. BALPA said last week that it would be willing to call it off if British Airways returned to the negotiating table.
According to its website, BALPA represents more than 10,000 pilots in the United Kingdom — more than 85% of all commercial pilots who fly there.
The pilot's union also intends to strike September 27. British Airways said Monday that it will be in contact "in the next few weeks" to let customers who are traveling on or around that date know if they are affected.
While the union is calling for higher wages, British Airways has said its offer of an 11.5% increase over three years "fair" and above the United Kingdom's current rate of inflation.
In a statement released last month, it said the strike could "destroy the travel plans of tens of thousands of our customers." It called the strike "a reckless course of action."