Reuters - The United States cannot unilaterally cancel the 2015 nuclear deal between Iran and world powers, EU foreign policy chief Federica Mogherini said on Friday in reaction to President Donald Trump's decision not to certify the accord.

"We cannot afford as the international community to dismantle a nuclear agreement that is working," said Mogherini, who chaired the final stages of the landmark talks.

"This deal is not a bilateral agreement ... The international community, and the European Union with it, has clearly indicated that the deal is, and will, continue to be in place," Mogherini told reporters.

Mogherini said she spoke to U.S. Secretary of State Rex Tillerson immediately after Trump's speech on Friday. (Reporting by Robin Emmott and Julia Fioretti)