Trump urges allies to defend the Strait of Hormuz, but no one's fully signed on

U.S. President Donald Trump is urging other countries to help secure the Strait of Hormuz as Iran targets ships in the vital oil route, but so far there are few firm commitments.

In a social media post Saturday, Trump suggested that many countries were already prepared to send naval vessels to keep the waterway open. He named China, France, Japan, South Korea and the United Kingdom as countries that could "hopefully" deploy ships to help ensure freedom of navigation.

"Many Countries, especially those who are affected by Iran's attempted closure of the Hormuz Strait, will be sending War Ships, in conjunction with the United States of America, to keep the Strait open and safe," Trump wrote on Truth Social, describing the move as a shared responsibility for nations that depend on oil flowing through the narrow shipping channel.

With global air transport heavily disrupted and no clear end in sight, Iran's ability to choke off traffic through the strait between Iran and Oman, which is the conduit for a fifth of global oil and liquefied natural gas, has emerged with increasing urgency as a decisive threat to the global economy.

The conflict has halted most shipping through the passage and helped drive oil prices above $100 US a barrel. 

But in a follow-up post hours later, Trump's tone shifted. He said countries that receive oil through the strait "must take care of that passage," adding that the U.S. would help co-ordinate the effort.

The call effectively amounted to a public appeal for allies — and even geopolitical rivals like China — to contribute naval forces to a mission that could involve escorting tankers, clearing mines or deterring attacks on commercial shipping.

So far, the countries Trump mentioned have responded cautiously.

Britain says it is discussing possible options with allies, including sending naval ships or mine-hunting drones, but has not committed to deploying forces.

Japan has also stopped short of promising military support. Analysts told The Financial Times that any deployment could face legal and political hurdles because of the country's pacifist constitution, which limits its ability to participate in combat operations abroad.

France has previously signalled interest in escort missions for commercial shipping, but officials have framed those efforts as defensive and contingent on the security situation.

China and South Korea have not announced any plans to send warships.

U.S. Energy Secretary Chris Wright told NBC he has been "in dialogue" with some of the countries, without naming them, and said he expected China "will be a constructive partner" in reopening the strait.

Trump's request comes despite strained relations with some allies over the conflict. The U.S. president has publicly criticized Britain's stance earlier in the war, saying the once-close relationship was "not like it used to be."