UK Prime Minister Keir Starmer has informed US President Donald Trump that Britain will not participate in or support a proposed US-led naval blockade of Iranian ports, according to a Downing Street spokesperson. The decision was communicated during a phone call between the two leaders on Saturday, April 11, 2026.
The US request is reportedly linked to ongoing tensions over Iran's nuclear program and its support for regional militant groups. A blockade would aim to severely restrict Iran's oil exports and imports of goods. The UK government stated that such an action would require a clear international legal mandate, which it believes is currently lacking.
Analysts suggest the refusal marks a significant divergence in UK-US foreign policy under the new Labour government, which took office following the July 2024 general election. The UK has instead reiterated its commitment to diplomatic efforts alongside European partners to address concerns with Iran.
The White House has not publicly commented on the specific conversation. The Iranian government has previously warned it would consider any blockade an act of war and respond accordingly.
