ROME (AP) — Iran and the United States prepared for a fifth round of negotiations over Tehran’s rapidly advancing nuclear program Friday in Rome, with enrichment emerging as the key issue.

"The Obama administration invented the category of 'nuclear sanctions’ as an excuse to give the Ayatollah whatever he wanted for a nuclear deal," Sen. Ted Cruz said

Oil prices settled lower on Wednesday, after Oman's foreign minister said a fresh round of nuclear talks between Iran and the U.S. would take place later this week.

Iran's Supreme Leader Ayatollah Ali Khamenei slamm ed U.S. demands that Tehran end its uranium enrichment program, stating that he does not believe ongoing nuclear negotiations with the U.S. will yield results. Iran says its nuclear program is for civilian purposes and that its enrichment program is a source of national pride and not negotiable.

Iran nuclear talks, Iran's Foreign Minister declares enrichment a national achievement, stressing continuation with or without a deal.