Sanaa, May 6 (IANS): UN Special Envoy for Yemen Martin Griffiths said that a recent UN-brokered negotiation between the country's warring sides and other relevant parties has failed to produce any agreement.

The recently-concluded negotiation, which took place in Saudi Arabia and Oman, aimed to install a ceasefire across Yemen, including in the central province of Marib, where the Houthi rebels have been launching massive offensives on the governmental forces since February, reports Xinhua news agency.

"We have been discussing these issues for over a year now... Unfortunately, we are not where we would like to be in reaching a deal," Griffiths said in a statement on Wednesday.

"I will keep engaging the parties to the conflict and all involved and concerned actors and stakeholders to offer them opportunities to find common grounds to help advance the peace efforts," he added.

In February, the Houthis began a major offensive against the Saudi-backed Yemeni government army to capture the oil-rich province of Marib, which hosts over 2 million internally displaced people.

The UN aid agencies have warned the Houthis that the assault on Marib could lead to a major humanitarian catastrophe.

Yemen has been mired in a civil war since late 2014 when the Houthi militia seized control of several northern provinces and forced the internationally recognized government of President Abd-Rabbu Mansour Hadi out of the capital Sanaa.