Iranian Foreign Minister Abbas Araghchi said on Saturday that Tehran and Washington showed determination to move forward during talks in Muscat, although serious disagreements remain. He described the discussions as "much more serious" and said he was "cautiously optimistic" about the process and pace of negotiations.

"Some of the disagreements are serious, and some have their own complexities, but we are hopeful that we can move forward quickly, and the progress so far has been good. I am satisfied with the process and pace of the negotiations," he said.

Meanwhile, AP quoted a senior US official calling the talks "positive and productive." The official said both sides acknowledged that much work remains, and the sides agreed to meet again soon in Europe. The White House thanked Oman for hosting the talks.