Washington (CNN) The US has "slammed the brakes on" a United Nations Security Council resolution calling for a limited ceasefire and increased humanitarian aid in Yemen over concerns about angering Saudi Arabia, two sources tell CNN.

One source familiar with the negotiations over the resolution tells CNN the US "has slammed the brakes on," saying that "we can't support a resolution at the moment."

The source also said the move is at odds with what US Ambassador to the UN Nikki Haley has been signaling to her counterparts at the UN, since she was supportive of the planned resolution weeks ago.

'Threw a fit'

The reason for the delay continues to be a White House worry about angering Saudi Arabia, which strongly opposes the resolution, multiple sources say. CNN reported earlier this month that the Saudi crown prince, Mohammed bin Salman, "threw a fit" when presented with an early draft of the document, leading to a delay and further discussions among Western allies on the matter.

Sources say US concerns, which are shared by other nations -- including the United Arab Emirates and Kuwait, both of which support Saudi in the conflict -- hinge on the real possibility that if the Security Council resolution is voted through, Saudi Arabia or the Houthis, or both, won't show up for hoped-for talks that are expected to take place next month in Stockholm, Sweden.

The White House declined to comment, referring queries about the resolution to the US Mission to the United Nations. Officials there also refused to comment.

State Department spokesperson Heather Nauert responded, "Negotiating the Security Council Resolution is important as we look to increase international consensus around Yemen. Our main focus at this time is offering our support for UN Special Envoy Martin Griffiths who is making progress in his negotiations with the Republic of Yemen and the Houthi rebels."

This latest delay comes a week after President Donald Trump indicated that he will not take strong action against Saudi Arabia or the crown prince for the murder and dismemberment of Washington Post journalist Jamal Khashoggi. Secretary of Defense James Mattis and Secretary of State Mike Pompeo will brief lawmakers about the Khashoggi killing on Wednesday.

The move to slow the resolution could increase tensions with lawmakers from both parties who have expressed deep reservations about US support for the kingdom's war in Yemen and would like to censure Saudi Arabia for what its officials admit was a premeditated murder.

And it will continue to fuel questions about Trump's unusual deference to the kingdom.

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The draft resolution, crafted by the UK and obtained by CNN, is already seen by human rights groups as disappointingly watered-down: It calls for a ceasefire only in Hodeidah, the principal Red Sea port through which some 80% of humanitarian aid flows.

The resolution is not at all critical of Saudi Arabia, and in fact compliments Saudi action; it is critical only of the Houthi rebels, who are backed by Iran and have been fighting Saudi-led coalition forces while maintaining control of the capital, Sanaa.

Mattis said last Wednesday that peace talks would take place in Sweden, even as experts cautioned that there's no guarantee Saudi Arabia will take the steps needed for that to happen.

Although the resolution in its current form is far from harsh on the Saudis, sources with knowledge of the discussions tell CNN that Saudi Arabia views even calling for a ceasefire and urging more humanitarian aid as indirect criticism of the kingdom and its four-year-long intervention in Yemen.

'Hugely sensitive'

"The Saudis are hugely sensitive -- ultra, ultra sensitive -- to international perceptions," one source told CNN. "They hate criticism. And (the crown prince) brings a whole new level of paranoia about this."

The situation in Yemen is now viewed as the worst humanitarian crisis on the planet, with some 13 million Yemenis at risk of starving to death, according to the United Nations and human rights groups.

On Wednesday, five human rights groups had issued an unusually stark statement, saying the US will bear shared responsibility for what may be the largest famine in decades if it doesn't cease support for the Saudi-led coalition.

Save the Children said Wednesday that an estimated 85,000 children under the age of 5 may have died from extreme hunger or disease since the war began.

But one source says that any language on human rights or accountability should not be expected in the UN resolution, as that would be "unwelcome to the coalition" fighting the Houthis.

The source told CNN that the crafters of the draft resolution know it is unbalanced in its criticism solely of the Houthis, but "we are faced with a very stubborn set of allies. When you see this resolution not being critical of Saudis, some of that is because if they feel the entire world is against them, they'll continue this war."

The conflict, which began in 2015 as a civil war after the ouster of a strongman leader, gathered force when Saudi Arabia and allies entered the battle to counter what they saw as Iranian influence. The Gulf coalition received logistical and intelligence support from the US, UK and France, which have also been selling weapons to Saudi Arabia.

After nearly four years, the war has killed around 57,000 people, according to the Armed Conflict Location and Event Data Project, a crisis mapping project.

This story has been updated.