Senior figures from Yemen's dominant Houthi group are holding talks with U.S. officials in Oman to advance efforts to resolve the conflict in Yemen, the Riyadh-based Yemeni government said on Sunday.

A Saudi-led coalition began air strikes in Yemen in March in a campaign to restore Yemeni President Abd-Rabbou Mansour Hadi to power. Hadi fled in March, after the Iranian-backed Houthi rebels seized the capital Sanaa in September and then thrust into central and south Yemen.

Nearly 2,000 people have been killed in the conflict since March 19, according to the United Nations.

"We have been informed that there are meetings, at American request, and that a private American plane carried the Houthis to Muscat," Rajeh Badi, a spokesman for Yemen's government in exile told Reuters by telephone from the Saudi capital Riyadh.

The Yemeni government was not party to the talks, Badi said.

There was no immediate comment from the Houthis and from U.S. officials.

If confirmed, the Oman meeting would be the first between the Houthis and the United States, Saudi Arabia's main foreign ally, since the start of the war.

The United States has said it was providing arms and intelligence to Saudi Arabia during its campaign in Yemen.

"We hope that these talks are being held in the context of international efforts to implement U.N. Security Council resolution 2216," Badi said.

The resolution, adopted in April, includes a call on all parties in Yemen, including the Houthis, to immediately and unconditionally end violence.

U.N. Special envoy to Yemen, Ismail Ould Cheikh Ahmed, has renewed efforts to set a new date for Yemeni political factions to meet in Geneva for peace talks, which were postponed indefinitely after Hadi demanded delays.

Houthi spokesman Mohammed Abdul-Salam announced on May 23 that he had departed with an official delegation from the group to neighbouring Oman to discuss the conflict with the Omani government, a frequent peacebroker in the region.

Though a member of the six-state Gulf Cooperation Council which also includes Saudi Arabia, Oman has not participated Saudi-led air strikes.

Yemeni politicians who met Ould Cheikh Ahmed in Sanaa on Saturday said he had informed them that "indirect talks" were underway in Muscat between the Houthi delegation and U.S. officials through Omani mediation.

Officials from the U.N. envoy's team were not immediately available to comment.

Hadi has demanded the Houthis recognise his authority and withdraw from Yemen's main cities -- both points demanded by last month's U.N. Security Council resolution -- as preconditions for talks.

The Houthis say their expansion is part of a revolution against hardline Sunni Muslim militants and corrupt officials, and have demanded for an end to the Arab bombing before negotiations.