Omani Foreign Minister Sayyed Badr Al-Busaidi met with his Yemeni counterpart Ahmed Awad bin Mubarak in Muscat to discuss the international efforts aimed at achieving a state solution in Yemen, sources told Al-Arabiya TV.

The Yemeni minister arrived in Muscat on Saturday. He said his visit, which is part of his Gulf tour, aims to strengthen bilateral relations between the two countries.

The delegation's arrival, which would have required approval from Riyadh, demonstrates something of a step forward in negotiations. The Houthis have repeatedly demanded the re-opening of Sanaa airport before any ceasefire agreement.

Oman, which borders both Yemen and Saudi Arabia, is a close US ally but at the same time has good relations with Iran. It has regularly played the role of mediator in regional conflicts.

Muscat has hosted UN special envoy for Yemen Martin Griffiths and US envoy Tim Lenderking in recent weeks, while Iran's Foreign Minister Mohammad Javad Zarif met with Abdul Salam in Oman in late April.

On Monday Griffiths urged rival Yemeni forces to "bridge the gap" to reach a ceasefire, following talks in Sanaa with Houthi members.