Yemen's government delegation to peace talks left Kuwait on Monday after the rebel side rejected a draft peace plan proposed by the United Nations, its representatives said.

"We now leave Kuwait... but are not quitting the consultations and not ending them before August 7," said the delegation head, Foreign Minister Abdulmalek al-Mikhlafi.

UN envoy Ismail Ould Cheikh Ahmed set August 7 as the date for winding up the talks that began April but have failed to achieve any breakthrough towards ending Yemen's conflict.

"We will return any minute... if the other side agrees to sign" the UN proposal, which was accepted by the government but rejected by the rebels, Mikhlafi told reporters at Kuwait airport.

Government delegation spokesman Mohammed al-Emrani earlier told AFP: "We are leaving today after having completed our part in the talks.

"The ball is now in the rebels' court."

The delegation was returning to Riyadh, where it is based, after informing the UN envoy that it was ready to sign the proposed peace plan, Emrani said.

Ould Cheikh Ahmed said he has received a letter from the government delegation agreeing to a "draft peace agreement proposed by the United Nations to resolve the conflict in Yemen".

"The departure of the government of Yemen delegation from Kuwait is not a departure from the peace talks," the envoy said in a statement.

He said he will hold intensive talks with the Huthis and their allies.

The Iran-backed Huthi rebels and their allies, former president Ali Abdullah Saleh's loyalists, rejected the peace plan on Sunday, saying it was incomplete.

"The other party now has the key to make the talks fail or succeed... If they agree to the plan, our delegation will return," Emrani said.

Mikhlafi lashed out at the rebels for rejecting the peace plan.

"This Huthi-Saleh alliance will never accept any peace deal that does not legitimise their coup," Mikhlafi said.

The government delegation's decision to leave host country Kuwait came after a meeting with the UN envoy.

The government delegation had been due to quit negotiations and leave Kuwait on Saturday but cancelled the decision after Ould Cheikh Ahmed presented the draft peace plan.

According to the government, the draft plan calls for the rebels to withdraw from the capital Sanaa and two major cities, hand over heavy arms and return state institutions they seized in September 2014.

- Rebels want unity govt first -

The rebels said that first a national unity government must be formed and a new consensus president appointed to oversee the transition.

Yemen, home to what the United States sees as Al-Qaeda's deadliest franchise, descended into chaos after the 2012 ouster of longtime strongman Saleh.

Security deteriorated further after the Huthis swept into Sanaa and pushed south, forcing President Abedrabbo Mansour Hadi's government to flee into exile in March last year.

The United Nations says the conflict has killed more than 6,400 people and displaced 2.8 million since then, when a Saudi-led Arab coalition launched a military campaign in support of Hadi.

On Monday, shelling from Yemen killed four people in the Jazan border region of Saudi Arabia, authorities in the kingdom said.

Source: AFP