In issuing Iran an invitation to the conference, Ban explained "the expanded international presence on that day," with last-minute invitations also sent to Australia, Belgium, Greece, the Holy See, Luxembourg, Mexico, the Netherlands, and South Korea, "will be an important and useful show of solidarity in advance of the hard work that the Syrian Government and opposition delegations will begin two days later in Geneva."
Ban spoke with Iranian Foreign Minister Javad Zarif regarding Iran's participation, with the Iranian official assuring the UN "Iran understands that the basis of the talks is the full implementation of the 30 June 2012 Geneva Communique, including the Action Plan." Zarif, Ban said, "pledged that Iran would play a positive and constructive role in Montreux," with the goal of the conference "to establish, by mutual consent, a transitional governing body with full executive powers."
The issue of whether to invite Iran had been a point of contention, with the UN and Russian government pressing the United States to agree to Iran's participation. As recently as January 13, U.S. Secretary of State John Kerry sparred with his Russian counterpart and a UN envoy during a press conference about Iran's potential attendance at Geneva II, with Kerry citing concerns about Iran's support of Hezbollah both within Syria and across the border in Lebanon as well as ambiguity whether Iran was a supporter of the Geneva I agreement.
State Department spokesperson Jen Psaki responded on Sunday to the UN's announcement, underlining that the U.S. views the UN invitation to Iran as "conditioned on Iran's explicit and public support for the full implementation of the Geneva communique including the establishment of a transitional body by mutual consent with full executive authorities."
The UN is the convener of Geneva II, with both the U.S. and Russia serving as co-hosts for the peace talks.