The U.S. Navy has decided to ground all 197 training jets indefinitely, following an exclusive Fox News report earlier this week that U.S. Navy pilots are refusing to fly the T-45 training jet because they say there is poison in the oxygen system.

“The pause is extended as long as our experts need as they diligently work to determine the root cause of the physiological episodes and solutions to fix the issue,” said Lt. Leslie Hubbell, a Navy spokesperson told Fox News Saturday.

Previously the Navy announced a three-day “pause” to the flight schedule, which was supposed to expire on Monday.

The heads of naval aviation and experts have been meeting with the instructor pilots at three bases across the United States in Mississippi, Texas, and Florida. Senator Roger Wicker, R.-Miss., a member of the Senate Armed Services Committee, is meeting the heads of naval aviation as well on Saturday in Meridian, Mississippi.

In the last five years, physiological episodes, caused in part by problems with the oxygen system, nearly have quadrupled on the T-45 training jet, according to Capitol Hill testimony last week by senior naval aviators.

The T-45 is used to train all U.S. Navy student pilots in jet aircraft. The pilots will eventually fly F/A-18 Hornets, EA-6B Prowlers, and the E-2 Hawkeye.

Fox News' Lucas Tomlinson contributed to this report.