Under pressure from the United States, U.N. Secretary-General Ban Ki-moon on Monday withdrew an invitation for Iran to participate in a Syria peace conference. U.N. officials had surprised the U.S. with the invitation, prompting Washington to insist that Iran be excluded because it had not agreed to the conditions for the talks, to be held in Montreux, Switzerland. The invitation also angered Saudi Arabia, Iran's regional rival, which threatened to boycott the talks if it wasn't rescinded. The conditions for the conference were outlined in a communiqué from a 2012 meeting in Geneva. Ban's about-face came just 48 hours before the start of the conference.