A top US general says Iran has complied with the terms of the 2015 nuclear agreement, warning Washington that leaving the landmark deal will have harmful consequences for the US.

US Chairman of the Joint Chiefs of Staff General Joseph Dunford said on Tuesday that the government in Tehran had acted in compliance with the deal between Iran and the P5+1 group of countries, known as the Joint Comprehensive Plan of Action (JCPOA), adding that a decision to walk away from it would make other nations less likely to enter into agreements with the US in the future.

“The briefings I have received indicate that Iran is adhering to its JCPOA obligations,” Dunford said. “It makes sense to me that our holding up agreements that we have signed, unless there is a material breach, would have an impact on others’ willingness to sign agreements.”

Speaking before the Senate Armed Services Committee, the top US military general claimed that the accord had “delayed” Iran’s nuclear program, also accusing Tehran of “malign activity” in the region.

Dunford made the remarks days after US President Donald Trump called the deal an “embarrassment to the United States,” and said he was considering whether to withdraw Washington from the 2015 deal.

On Monday, the ambassadors to the United States from Britain, France, Germany and the European Union all strongly backed the nuclear agreement with Iran.

The JCPOA was reached between Iran and the five permanent members of the UN Security Council – the United States, France, Britain, Russia and China – plus Germany in July 2015 and took effect in January 2016.

The Trump administration has desperately sought a pretext to scrap or weaken the 2015 deal and get rid of the limits the deal imposes on the US ability to pursue more hostile policies against Iran.

The Republican president faces an October 15 deadline for certifying that Iran is complying with the deal. If Trump refuses to do that, then the Republican-controlled Congress will have 60 days to decide whether to reimpose sanctions waived under the deal. That would let Congress effectively decide whether to kill the deal.

However, the European ambassadors vowed to do everything possible to protect any companies based in Europe that continue to do business with Iran from reimposed US sanctions in case of Washington’s withdrawal from the JCPOA.

The International Atomic Energy Agency has repeatedly verified Iran’s adherence to the terms of the JCPOA, while the other parties to the deal, along with the entire international community, have thrown their weight behind the accord, praising the Islamic Republic for its full commitment to its side of the bargain.