US President Donald Trump is questioning whether or not the US should continue to protect ships in and around the Strait of Hormuz, where six tankers have been attacked in as many weeks.

"China gets 91% of its Oil from the Straight [sic], Japan 62%, & many other countries likewise," Trump tweeted Monday morning. "So why are we protecting the shipping lanes for other countries (many years) for zero compensation[?]

"All of these countries should be protecting their own ships on what has always been ...