U.S. President Donald Trump said the U.S. is "locked and loaded depending on verification" that Iran staged the attack on major Saudi Arabian oil facilities, an assertion already made by his secretary of state and backed by administration officials.

"There is reason to believe that we know the culprit, are locked and loaded depending on verification," Trump said on Twitter on Sunday without mentioning Iran or specifying what the response would entail. He said he's awaiting word from Saudi Arabia about who it believed caused the attack and "under what terms we would proceed!"

The massive strike on the world's largest crude-processing facility operated by Saudi Arabia's Aramco has global ramifications, particularly for countries in Asia. The region consumes more oil than anywhere else, with China, India, Japan and South Korea among the world's top buyers.