US president says it is ‘only appropriate’ for Europe to help, and warns failure to do so would be ‘very bad’ for Nato

• Middle East crisis – live updates

Donald Trump has ratcheted up the pressure on European allies to help protect the strait of Hormuz, warning that Nato faces a “very bad” future if its members fail to come to Washington’s aid.

The effective closure of the vital waterway by Tehran in retaliation for airstrikes by the US and Israel has proved catastrophic for global energy and trade flows, causing the largest oil supply disruption in history and soaring global oil prices.