U.S. Special Envoy Steve Witkoff plans to meet Iranian Foreign Minister Abbas Araghchi in Oman on Sunday and discuss Iran’s response to a recent American proposal for a nuclear deal, a U.S. official said late on Wednesday.

Iran said on Monday it will soon hand a counter-proposal for a nuclear deal to the United States in response to a U.S. offer that Tehran deems “unacceptable,” while U.S. President Donald Trump said talks would continue.

Trump told a podcast on Monday he was less confident that Iran will agree to stop uranium enrichment in a nuclear deal with Washington.

Trump has been seeking a new nuclear deal to place limits on Iran’s disputed uranium enrichment activities and has threatened the Islamic Republic with bombing if no agreement is reached.

Iran has long said it has no plans to develop nuclear weapons and is only interested in atomic power generation and other peaceful projects.