American Airlines said on Sunday it would cut back some flights in July, even though its seen demand for air travel suddenly rise.An increase in U.S. vaccination rates, and the easing of travel restrictions in recent weeks, seemed to have helped a surprise uptick in travel.But the unexpected resurgence has put a strain on American Airlines' operations. The airline said that unprecedented weather has caused multi-hour delays over the past few weeks, disrupting flight and crew working hours.It also said it is dealing with labor shortages at some of its hub airports.On Sunday, the company said it will cancel about 1% of flights next month.In a statement it said the move would "minimize surprises at the airport."The company also said it would be adjusting flights in markets that had 'multiple options for re-accommodation', to minimize the impact to customers. According to the U.S. Transportation Security Administration, nearly 50 million airport passengers were registered in May.That's up 19% from April. Already in June, the TSA has registered 35 million air passengers so far.