French President Emmanuel Macron has urged his US counterpart, Donald Trump, to stick with the Iran nuclear deal, saying there is no better option.
He was speaking to Fox News ahead of a three-day state visit to the US starting on Monday.
Mr Trump has threatened to abandon the deal, which limits Iran’s nuclear programme in return for sanctions relief, unless it is toughened up.
He has until 12 May to decide whether to restore US sanctions against Iran.
Correspondents say such a move would effectively kill the landmark agreement between Iran and six major western powers.
The two leaders are expected to address the issue when Mr Trump hosts Mr Macron this week.
Mr Macron told Fox News he had no “plan B” for the deal if the US decided to restore sanctions, and said the US should stay in the agreement as long as there was no better option.
“Let’s present this framework because it’s better than the sort of North Korean-type situation.”
He said the two leaders had “a very special relationship” and he wanted to address ballistic missiles as part of the deal – a key demand of the US president – as well as work to contain Iran’s influence in the region.
President Trump is also demanding that signatories to the deal agree permanent restrictions on Iran’s uranium enrichment. Under the current deal they are set to expire in 2025.
He has put pressure on his European co-signatories to address these issues before the 12 May deadline, when he needs to decide whether to sign a waiver giving sanctions relief to Iran.
Under US law, passed during the Obama administration, the president needs to sign these waivers every 120-180 days acknowledging Iran’s compliance with the deal.
When Mr Trump signed the last one, in January, he said it was a “last chance” to change the accord, before the US withdraws.
Iran’s Foreign Minister Javad Zarif warned on Saturday that his country was prepared to resume its nuclear programme “at much greater speed”, if the US withdrew from the accord.
Mr Macron also appealed to the US president not to pull troops out of Syria after the final defeat of so-called Islamic State, saying that would “leave the floor” to Iran and Syria’s President Bashar al-Assad.