NEW YORK — Iran has been invited to attend a meeting of foreign ministers in the Swiss city of Montreux on Wednesday ahead of internationally brokered peace talks between Syria’s warring factions, U.N. Secretary-General Ban Ki-Moon said Sunday.

Ban said he had issued the invitation to Iran after “speaking at length in recent days” with Iranian Foreign Minister Javid Zarif, who had “pledged that Iran would play a positive and constructive role in Montreux.”

Ban said Iran is among 10 additional countries invited to attend the Montreux meeting that precedes the peace talks scheduled to begin Friday between Syrian President Bashar Assad’s delegation and Syrian opposition groups at the U.N. European headquarters in Geneva. Thirty other countries had already been invited to attend the Montreux meeting.

Invitations to the one-day meeting of foreign ministers at a Montreux hotel had been subject to approval by the initiating states, Russia and the United States, but the two countries had been at an impasse over whether Iran, Assad’s strongest ally, should attend.

Secretary of State John Kerry had said he would welcome Iran’s participation – but only if Tehran endorsed earlier diplomatic agreements that called for a transitional government in Syria that would be created by mutual consent among the Syrian factions.

Ban said that Zarif had assured him that Iran “understands that the basis of the talks” is the full implementation of the road map adopted by the United States, Russia and other major powers in Geneva in June 2012. That plan called for the creation of a transitional Syrian government with full executive powers.

“Foreign Minister Zarif and I agree that the goal of the negotiations is to establish, by mutual consent, a transitional governing body with full executive powers,” Ban said. “It was on that basis that Foreign Minister Zarif pledged that Iran would play a positive and constructive role in Montreux.”

Ban said he believed that the expanded international presence in Montreux “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.”

He reiterated that he believes “Iran needs to be part of the solution to the Syrian crisis.”