Oman has announced that pllanned negotiations between Iran and the United States this weekend over Tehran’s rapidly advancing nuclear program have been postponed.

Iran accused the United States of “contradictory behavior and provocative statements” after the U.S. condemned the country for sponsoring the Yemen-based Houthis amid nuclear talks. The U.S. and Iran have been holding negotiations in Oman over the past month to make a deal to curb Iran’s nuclear program in exchange for the U.

Iran will hold talks in Rome on Friday with European parties to their now moribund 2015 nuclear deal, its foreign minister said on Wednesday, as both sides seek to position themselves ahead of a new round of U.