(Adds Houthi leader comments)
* U.N. chief sets Yemen talks for Geneva on May 28
* Yemeni foreign minister taken aback by announcement
* Iran agrees to let international inspection of aid ship
* Saudi-led forces bomb Sanaa, Saada
By Louis Charbonneau and Sam Wilkin
UNITED NATIONS/DUBAI, May 20 (Reuters) - U.N. chief Ban Ki-moon on Wednesday announced talks between warring Yemeni parties in Geneva on May 28 to end over seven weeks of war, as Iran agreed for international inspections of an aid ship sailing to Yemen.
The moves are aimed at defusing the deepening crisis in the southern Arabian Peninsula, where Saudi-led forces killed at least 15 Houthis in the latest air strikes of a campaign to restore President Abd-Rabbu Mansour Hadi.
Sunni Muslim Saudi Arabia and regional Shi'ite powerhouse Iran are in a tussle over influence in the Middle East, where sectarian tensions are fuelling civil strife in Syria and Iraq that has killed hundreds of thousands of people.
"The Secretary-General is pleased to announce the launch of inclusive consultations starting on 28 May in Geneva to restore momentum towards a Yemeni-led political transition process," the U.N. statement issued in New York said.
A U.N. Security Council source said Ban was expected to attend the opening session.
In New York, the U.N. Security Council met behind closed doors to discuss the Yemen crisis. It issued a statement urging "all Yemeni parties to attend these talks and engage without preconditions and in good faith," while also calling for the resumption of humanitarian pauses in the fighting.
The foreign minister of the exiled Yemeni government based in Saudi Arabia appeared surprised by the announcement and said the Houthis must first disarm and quit cities they seized since last September first.
"We didn't get an official invitation," Reyad Yassin Abdulla said by phone. "It's very short notice. If it happens, it shouldn't be on May 28," he added.
But Yemen's U.N. Ambassador Khaled Alyemany said all parties, including the Houthis, would attend.
"Of course President Hadi will be represented in Geneva," he told reporters in New York. "He might be sending Vice President and Prime Minister (Khaled) Bahah, he might be sending somebody else."
Houthi leader Abdel-Malek al-Houthi announced "conditions" for their attendance of the talks in a speech broadcast on Wednesday, including a commitment by parties to a controversial agreement after the Houthis' September takeover of the capital that integrated the militia into all the state's institutions.
"The only way to solve the political problem is dialogue in a neutral country over what has been agreed upon in advance in the peace and partnership agreement," al-Houthi said.
A conference organised by the Yemeni government, which was not attended by the Houthis, concluded in Riyadh on Tuesday by calling on the Houthis to drop their weapons and withdraw from the cities they had captured before any talks could begin.
IRANIAN AID SHIP INSPECTION
The U.N. announcement came as Iran announced that the Iranian cargo ship sailing to Yemen with 2,500 tonnes of food and medical supplies would submit to international inspections in Djibouti before continuing on to Yemen's Hodaida port, which is under Houthi control.
The move reduces the risk of a potential showdown between the vessel, which had been escorted by Iranian warships, and Saudi-led forces enforcing inspections on vessels entering Yemeni ports to prevent arms supplies from reaching the Houthis.
"We have decided to dock our ship in Djibouti so the United Nations inspection protocol can take place," Iran's Deputy Foreign Minister Hossein Amir Abdollahian was quoted as saying by the ISNA news agency.
The voyage had threatened to escalate a regional confrontation over Yemen, in which Saudi Arabia and its Sunni Muslim allies have carried out almost two months of air raids on Houthi fighters it says are armed by Shi'ite power Iran. Tehran dismisses the allegation.
Saudi-led forces have imposed searches on all ships trying to enter Yemen to prevent weapons reaching the Houthis, who control much of the country.
Reuters ship tracking data showed the Iran Shahed positioned southwest of Aden at 1446 GMT on Wednesday.
Residents said on Wednesday that overnight, warplanes carried out the most sustained bombardment of Yemen's capital Sanaa since the offensive started, hitting army bases and weapons depots.
The coalition has been bombing Houthi forces since March 26 in a bid to restore Hadi to power after the Shi'ite Muslim group forced him to flee the country.
Tribal sources along the Saudi-Yemeni border also said that more than 15 Houthi fighters and at least one Saudi officer were killed in intense clashes along their common border near the Saudi city of Najran.
Planes also bombed a Yemeni army camp in the northern border province of Hajjah. Residents said huge explosions had been heard at the camp, in a sign the strike might have hit missile storage facilities. (Reporting by Lou Charbonneu at the United Nations, Sam Wilkin and Noah Browning in Dubai and Mohammed Ghobari in Cairo, Writing by Sami Aboudi and Angus McDowall; Editing by Tom Heneghan)