The chairman of the House Armed Services Committee said Friday that a decision to ground all Marine aircraft for 24 hours is "indisputable evidence" that the military is dangerously degraded.

The service announced Friday that all aircraft units are required to halt flights for a refresher course on safe operations following two deadly crashes this summer.

"The Marine Corps decision to temporarily ground all aircraft is further, indisputable evidence that America's military is in a readiness crisis, and that the crisis is costing lives," Rep. Mac Thornberry, R-Texas, said.

Thornberry has been a top advocate on Capitol Hill for a big hike in defense spending and has criticized President Trump's $603 billion proposed 2018 budget as far too meager. Armed Services crafted a $696 billion defense bill that passed the House last month.

"Washington has asked our military to do too much with too little for too long," he said in a released statement. "As threats continue to grow, Congress must act as soon as possible to provide our military with all of the resources they need to repair what can be fixed and replace what cannot be repaired."

Three Marines were killed last week when a tilt-rotor MV-22 Osprey aircraft went into the ocean off the coast of Australia during a training mission and 15 Marines and a Navy corpsman were killed July 10 when a Marine KC-130 refueling tanker smashed into a field in Mississippi.

Gen. Robert Neller, the Marine Corps commandant, said commanders are allowed to choose aircraft are grounded but the daylong training must be completed over the next two weeks across the Marine Corps, said.

"The intent is for flying squadrons to review selected incidents which occurred enterprise-wide and study historical examples of completed investigations in order to bring awareness and best practices to the fleet," the service announced.