Trump also asked Congress for nearly $88 billion in supplemental funding, mostly to cover the spiralling cost of the war, just a day after Congress called on him to end the conflict unless lawmakers explicitly authorise military action.

Tehran has emerged emboldened from the war, vowing not to relinquish control of the vital waterway and going so far as to call its initial deal with Washington to stop the fighting "a declaration of America's defeat".

Iran slammed NATO on Thursday after Rutte noted its support for the United States, with foreign ministry spokesman Esmaeil Baqaei accusing the transatlantic bloc of "complicity" in the "unlawful war".

During a visit to Kuwait City, Rubio said Washington would be on the same page as Gulf states as it wrangles with Iran over a permanent settlement to the conflict.