The European Union and Tehran are expected to show support for Iran's 2015 nuclear agreement with world powers at a foreign ministers' meeting on January 11 while the White House is deciding whether to continue backing the agreement.
At a meeting hosted in Brussels by European foreign policy chief Federica Mogherini on January 11, European powers that helped to negotiate the accord were expected to reassure Iran that they remain committed to it.
Reuters quoted a European diplomatic source as saying "the aim is to send a message to Washington that Iran is complying, and that it is better to have the nuclear agreement than to isolate Tehran."
The meeting comes one day before a U.S. deadline requiring President Donald Trump to once again decide whether the U.S. will continue backing the deal.
The agreement requires Iran to curb nuclear activities in exchange for sanctions relief.
Many of Trump's top aides have reportedly been urging him to extend U.S. sanctions relief, but Trump remained reluctant on January 10.
Trump and key advisers reportedly will meet on January 11 to finalize the decision, which will be revealed on January 12.
Reports said Secretary of State Rex Tillerson, Defense Secretary James Mattis, and National Security Adviser H.R. McMaster were pressing Trump to sign the waiver granting Tehran relief.
Trump on January 12 is facing another quarterly deadline for certifying whether Iran is in compliance with the deal.
The president is a fierce critic of the accord and refused to certify Iran's compliance with the deal at the last deadline in October. Still, he has so far stopped short of withdrawing the United States from the accord.
Iran on January 10 warned that it would pull out of the nuclear deal if the United States leaves.
"In case the Americans exit the deal, we will react in no time flat," Majid Tacht Rawanchi, an adviser to President Hassan Rohani, was quoted as saying by Iran's state-run IRNA news agency.
The other signatories to the accord -- Britain, China, Germany, France, and Russia -- and the EU continue to support the agreement.
Meeting Iranian Foreign Minister Mohammad Javad Zarif in Moscow on January 10, Russian Foreign Minister Sergei Lavrov vowed that Moscow would defend the agreement as a "key contribution to regional stability and nuclear nonproliferation.”
To counter Trump’s reluctance to waive sanctions, sources said, top aides are proposing that the president instead impose new targeted sanctions on Iranian businesses and people related to its ballistic-missile and nuclear programs.
The sources said the new sanctions could hit some people and companies given relief under the 2015 agreement -- a move that would increase pressure on Tehran but would not mean a pullout from the accord.
The White House and State Department did not immediately respond to requests for comment.