Gulf countries are locked in tough negotiations with Russia on a UN draft resolution to impose an arms embargo and sanctions on Yemen, diplomats said Wednesday.

The resolution would seek to re-launch a political dialogue that broke down after Yemen's Shiite Houthi rebels pressed ahead with an offensive, forcing President Abd Rabbo Mansour Hadi to flee to Saudi Arabia.

The six-nation Gulf Cooperation Council (GCC) has been negotiating with the five permanent Security Council members and Jordan on a text after Saudi Arabia launched an air campaign on Yemen on March 23, without a UN mandate.

The GCC is no longer seeking a resolution that supports Saudi-led military action in Yemen, which it argues is legal because it is being carried out at Hadi's request, diplomats said.

But its push for an international arms embargo and sanctions targeting the Houthis has run into major opposition from Russia, which has friendly relations with Iran.

Saudi Arabia accuses Iran of backing the Houthis in their power grab as part of a bid to extend its regional influence.

"The GCC will now need to lobby the Russians very, very hard," said a Security Council diplomat, who spoke on condition of anonymity.

During negotiations, Russia presented amendments to the draft resolution that would extend an arms embargo to all sides, including Hadi's forces in the conflict, diplomats said.

Moscow also opposed sweeping sanctions against the Houthis and requested that a list be submitted of individual names of rebel leaders who could be targeted for a global travel ban and assets freeze.

Spokesman Aleksey Zaytsev from Russia's UN mission confirmed that "there are problems" with the resolution, but declined to give details.

Talks on how to address the crisis in Yemen came amid mounting UN concern over the civilian toll from the seven-day Saudi-led air campaign.

At least 62 children have been killed over the past week, according to the UN children's agency UNICEF and aid agencies are alarmed about the fate of civilians trapped in the fighting.

UN negotiations on Yemen are being held against the backdrop of six-power talks in Switzerland with Iran on a nuclear deal that could change the power dynamics in the Middle East.