DUBAI, United Arab Emirates — Iran’s president said Sunday that the Islamic Republic rejected direct negotiations with the United States over its rapidly advancing nuclear program, offering Tehran’s first response to a letter that U.S. President Donald Trump sent to the country’s supreme leader.

President Masoud Pezeshkian said that Iran’s response, delivered via the sultanate of Oman, left open the possibility of indirect negotiations with Washington. However, such talks have made no progress since Trump in his first term unilaterally withdrew the U.S. from Tehran’s nuclear deal with world powers in 2018.

In the years since, regional tensions have boiled over into attacks at sea and on land. Then came the Israel-Hamas war in the Gaza Strip, which saw Israel target militant group leaders across Iran’s self-described “Axis of Resistance.” Now, as the U.S. conducts intense airstrikes targeting the Iranian-backed Houthi rebels of Yemen, the risk of military action targeting Iran’s nuclear program remains on the table.

“We don’t avoid talks; it’s the breach of promises that has caused issues for us so far,” Pezeshkian said in televised remarks during a Cabinet meeting. “They must prove that they can build trust.”

The U.S. State Department, responding to Pezeshkian, said, “President Trump has been clear: the United States cannot allow Iran to acquire a nuclear weapon.”

It added, “If the Iranian regime does not want a deal, the president is clear, he will pursue other options, which will be very bad for Iran.”