US President Donald Trump and Iran's president signed a deal Wednesday meant to end the Middle East war, with Tehran agreeing to dilute its enriched uranium in return for large-scale economic relief.

Trump put his signature to the memorandum of understanding during a candlelit dinner at the Palace of Versailles following a G7 summit, as host French President Emmanuel Macron and other guests applauded, a video posted by a Trump aide showed.

"Just signed it," Trump told reporters as he emerged from the palace.