The U.S. submarine strike on the Iranian vessel came as U.S. President Donald Trump pledged to provide insurance and navy escorts to ships exporting oil and gas from the Middle East in a bid to contain soaring energy prices. At least 200 ships, including oil and liquefied natural gas tankers as well as cargo ships, remained at anchor in open waters off the coast of major Gulf producers including Iraq, Saudi Arabia and Qatar, according to Reuters estimates based on ship-tracking data from the MarineTraffic platform.