Donald Trump has signed a hard copy of the initial agreement with Iran to extend the ceasefire between the US and Iran for another 60 days, laying the groundwork for reopening the Strait of Hormuz and launching negotiations on Iran's nuclear program.

"It's signed," Trump said as he left the Palace of Versailles after attending a dinner hosted by French President Emmanuel Macron.

Iran's foreign ministry spokesperson said the agreement had been digitally signed by President Masoud Pezeshkian.

Pakistan's prime minister, a key intermediary between the US and Iran, said the agreement had entered into force with "immediate effect" after both sides signed it.