ARLINGTON, Virginia (Reuters) -Hundreds of U.S. air traffic controllers have taken temporary second jobs as they miss their first full pay check on Tuesday, putting more pressure on the strained aviation safety system, a union official said Tuesday.

National Air Traffic Controllers Association President Nick Daniels told reporters at Reagan Washington National Airport that the number would rise as more controllers look for ways to pay bills.

"It's quickly going to be 1,000," Daniels said, calling on the government to end the standoff. "We want the shutdown to end today... Whatever way that it gets done, that's what the American people deserve."