Breaking: US and Iran sign memorandum aimed at ending war

Donald Trump has warned Iran he is prepared to resume fighting if the deal falls thourgh. (Reuters: Evan Vucci)

The presidents of the United States and Iran have officially signed a memorandum of understanding aimed at ending their war and reopening the Strait of Hormuz.

The agreement was due to be signed at an official ceremony in Switzerland on Friday but the White House and Iranian state media confirmed it had been signed early.

Earlier today, in a briefing with journalists including from the ABC, a senior US official read out the full text of the 14-point document.

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The agreement says the Strait of Hormuz will be toll-free for 60 days, but it leaves open the possibility that tolls may be imposed in the future. However, a senior US official expressed confidence that would not happen.

It also includes a $US300 billion ($424 billion) reconstruction fund for Iran but US officials say this does not mean the US will be financially involved.

The document reiterates Iran's commitment that it will not procure or develop nuclear weapons but it leaves the key questions around the nuclear program to final negotiations.