Reaching a deal with Iran will test the harder-line wing of Mr. Trump’s supporters in the Republican Party and whether they will fall in line with what would be a departure from their longstanding demands that Iran dismantle its nuclear program. More than 200 congressional Republicans urged him in a letter this week to stand firm with Iran.

US President Donald Trump said on Thursday that Washington is “very close” to reaching a nuclear deal with Iran after Tehran “sort of” agreed to its terms.

President Donald Trump on Friday said Iran had a U.S. proposal about its nuclear program and knows it needs to move quickly to resolve a decades-long dispute, but Tehran denied receiving one yet.