Investing.com -- Major U.S. stock averages pared earlier gains Wednesday morning after President Trump expressed frustration about the U.S. being responsible for keeping the Strait of Hormuz open without help from allies.

Trump wrote on Truth Social, "I wonder what would happen if we ’finished off’ what’s left of the Iranian Terror State, and let the Countries that use it, we don’t, be responsible for the so called ’Straight?’ That would get some of our non-responsive ’Allies’ in gear, and fast."

S&P 500 futures remained up 0.3% following the comments, while crude prices were slightly lower Wednesday morning but both markets reacted to the Truth Social post.

The European Union made it clear Tuesday that it would not be racing to meet Trump’s calls for military assistance to reopen the Strait of Hormuz. The 27-nation bloc includes some of America’s closest allies.

The war launched by the U.S. and Israel against Iran has seen traffic through the vital shipping lane grind nearly to a halt due to Tehran’s retaliatory missile and drone fire across the Persian Gulf. Roughly a fifth of all crude oil supplies typically pass through the strait, causing a sharp rise in global energy prices.

Trump has issued repeated demands that European allies deploy warships to help protect commercial vessels navigating the strait. The allies were cut out of the planning ahead of the assault on Iran.