Yemen's exiled President Abd-Rabbu Mansour Hadi has said he is prepared to travel to Geneva for peace talks with Shia rebels who have taken over large swaths of the country, an aide to the embattled leader has said.

A spokesman for the government told Al Jazeera on Tuesday that the administration was prepared to come to "consultations" about the situation.

However, the Yemini government said it would not negotiate with Houthi rebels until they comply with a UN resolution to pull out of all occupied territory.

The talks in Switzerland had been previously postponed and no new date for the UN-led talks has been officially announced.

A UN official said it is hoped the talks would begin by June 10, the AP news agency reported.

Hostages released

The US state department said on Tuesday that senior US diplomats met representatives of the Houthi rebels in Muscat, Oman's capital, for a day last week to discuss a political solution to Yemen's conflict.

"These meetings in general were part of our broad engagement with elements of the Yemeni political spectrum," state department spokeswoman Marie Harf told a briefing.

"We used that meeting to reinforce our view that there can only be a political solution to the conflict in Yemen, and that all parties, including the Houthi, should commit to participation in the UN-led political process."

The meeting was led by US Assistant Secretary of State for Near-Eastern Affairs Anne Patterson, who also travelled to Jordan and Saudi Arabia to discuss a ceasefire in Yemen, Harf said.

The department also said that it pressed for the release of US hostages held by the rebel group.

On Monday, the Omani air force brought back two hostages - an American and a Singaporean - who had been held in Sanaa, Yemen's capital.

Both hostages are in a stable condition. The Singaporean Ministry of Foreign Affairs said on Tuesday that there are still more than 30 registered Singaporeans in Yemen.