UN Security Council members will begin talks on Tuesday on a US-and Bahrain backed draft resolution that could lead to sanctions against Iran, and potentially authorise force, if Tehran fails to halt attacks and threats to commercial shipping in the Strait of Hormuz, three Western diplomats said.

Fresh exchanges of fire on Monday underscored the stakes as the US and Iran struggle for control of the narrow waterway, a vital artery for global energy and trade, shaking a fragile four-week-old truce and reinforcing rival maritime blockades.

The US diplomatic push at the United Nations is in stark contrast to recent months during which it has largely acted outside the U.N. framework, launching military strikes against Iran without seeking council authorisation and pressing allies to join ad hoc naval patrols to enforce freedom of navigation.

That approach drew resistance from partners wary of open-ended conflict and legal exposure, prompting sharp criticism from US President Donald Trump against countries he accused of failing to align with US-led efforts.

Monday’s escalation, in which the US said it destroyed six Iranian small boats and Iranian missiles hit a UAE oil port, followed Washington’s launch of “Project Freedom”, a US led effort to move stranded tankers and other vessels through Hormuz.

Against that backdrop, the draft resolution forms part of what the diplomats described as a strategy to pressure Iran diplomatically and plan for a post-conflict situation.

Washington has also circulated a proposal, seen by Reuters, to partners for a new multinational maritime coalition, the Maritime Freedom Construct (MFC), aimed at establishing a post conflict security architecture for the Middle East and reopening the Strait once conditions stabilise.

An earlier Bahraini resolution that was backed by the United States and appeared to open a path to legitimise its military action against Iran failed after Russia and China blocked it.

The new draft takes a more cautious approach, avoiding explicit language authorising force while still operating under Chapter VII of the UN Charter, which allows the Security Council to impose measures ranging from sanctions to military action.