The United Nations envoy to Yemen met President Abd-Rabbu Mansour Hadi on Saturday to discuss prospects for peace talks between his embattled Aden-based government and Houthi forces, the president's office said.

Forces loyal to Hadi backed by mainly Gulf Arab states have been locked in eight months of civil war with the Iran-allied Houthis who rule the capital Sanaa.

Previous UN-led efforts to end the conflict through dialogue have failed as battles rage across the country and Saudi-led warplanes bomb positions of Yemen's ascendant Houthi group and its Yemeni army allies.

A source in the president's office said UN envoy Ismail Ould Cheikh Ahmed's talks with Hadi aimed to lay the groundwork for a second round of talks in the Swiss city of Geneva, and Hadi said in a statement he welcomed the efforts.

"Despite the suffering and wounds, our hands are always outstretched for peace based on national and humanitarian responsibilities towards our people," Hadi was quoted as saying after meeting the envoy, yet no date was declared for the talks.

It is the first time the envoy has paid an official visit to Aden, which Hadi declared the temporary capital after Arab coalition forces seized it from the Houthis in July.

But the government and its Gulf allies have struggled to impose their authority in the city, which teems with shadowy gunmen who carried out two shootings on Saturday.

Eyewitnesses said attackers on motor bikes shot dead Muhsin Alwan, a prominent judge in an anti-terrorism court, and his two sons inside a supermarket in the Aden district of Mansura. Gunmen killed a military police colonel in Mualla neighbourhood earlier in the day.

Al Qaeda in the Arabian Peninsula and more recently Yemen's branch of Islamic State have claimed credit for attacks in Aden.

Diplomats say the talks may take place this month in Switzerland, but some Yemeni officials have expressed scepticism that they will go ahead.

The Houthi group swept Hadi from power in February as part of it what called a revolution against corruption and accused Hadi of being beholden to Saudi Arabia and the West.

Gulf Arab countries led by Saudi Arabia intervened as the civil war worsened in March, fearing the group was acting as a proxy for its regional rival Iran, but making few gains toward retaking the capital in a war that has killed over 5,700 people.

Mistrust runs deep between Yemen's warring parties, with the Houthis believing the government wants to take back power by force and Hadi officials saying that the Houthis are refusing to withdraw from main cities as required by a U.N. Security Council Resolution passed in March.

"The government is ready for talks but the other side isn't, and its actions on the ground contradict their statements that they support a peaceful solution," Abdel-Malek al-Mekhlafi, who was named as foreign minister by Hadi last week, told Reuters.-Reuters