Pakistan, May 20 -- Iran's Supreme Leader Ayatollah Ali Khamenei said on Tuesday that nuclear talks with the United States are unlikely to lead to any meaningful outcome. His comments come amid growing uncertainty over diplomatic efforts to resolve tensions around Iran's uranium enrichment activities. Khamenei stressed that denying Iran's right to enrich uranium is a "big mistake" and signaled a lack of confidence in the ongoing dialogue.

Since April 12, Iran and the US have engaged in four rounds of Omani-mediated nuclear talks-the highest-level contacts since Washington exited the 2015 nuclear agreement. While both sides confirmed another meeting after their May 11 talks, Khamenei's remarks cast doubt on the prospects of progress. Iran...