She did not answer a question about whether the United States was committed to staying in the accord.
“The international community cannot afford dismantling an agreement that is working and delivering,” she told reporters outside the United Nations Security Council chamber.
Referring to North Korea’s nuclear program, Ms. Mogherini also said: “We already have one potential nuclear crisis. We definitely don’t need to go into a second one. This is an agreement that prevented a nuclear program and potentially prevented military intervention. Lets not forget that.”
“There is no need to renegotiate parts of the agreement because the agreement is working,” she added.
She spoke after the foreign ministers of six countries — Britain, China, France, Germany, Russia and the United States — had met along with their Iranian counterpart, Mohammad Javad Zarif.
Ms. Mogherini insisted that the European Union would ensure that the accord stayed in place. “As Europeans, we will make sure the agreement stays.”
Asked whether the Trump administration would quit the agreement, Ms. Mogherini said the accord belonged to no single country. “It’s not for one party or the other to certify this,” she said, noting that only the International Atomic Energy Agency had that responsibility.
“There are other issues that are out of the scope of the agreement and issues might be tackled in different formats, different fora.”
Secretary of State Rex W. Tillerson represented the United States; Nikki R. Haley, the United States ambassador to the United Nations, was also in the room. She left without taking questions.
— SOMINI SENGUPTA
Nicaragua, in reversal, supports climate accord
Daniel Ortega, the president of Nicaragua, has announced that his country would sign the Paris Agreement on climate change, a decision that will leave the United States and Syria as the only nations not part of the global accord.
The move came as the Trump administration has been sending mixed signals about whether it will abandon or remain in the pact of nearly 200 nations to curb greenhouse gases. It also comes as other leaders attending the United Nations General Assembly this week pledged to support the climate change goals.
Nicaragua initially objected to the Paris agreement because, its negotiators said, it did not compel rich countries to do enough to cut carbon emissions or to pay for the damages caused by climate change.
But in an…