U.S. President Donald Trump said he does not suspect foul play in two separate U.S. Navy aircraft crashes that occurred over the South China Sea this past weekend.

Speaking to reporters aboard Air Force One, Trump said he expected answers about the incidents soon, noting that one preliminary explanation involved faulty fuel.

“You’ve been briefed on the incident, on the Nimitz, both a fighter jet and a helicopter?” a reporter asked.

“I’ve heard about it, yeah,” Trump replied.

The comments follow weekend crashes involving a fighter jet and a helicopter operating from the aircraft carrier USS Nimitz, though the Navy has not publicly confirmed the causes.