The US rejected a request from the United Arab Emirates to provide military support to the Saudi-led coalition's operation to capture the Houthi-held port city of Hodeidah, Yemen, US and UAE officials tell CNN.
The US government rejected the coalition's request for intelligence, surveillance and reconnaissance support as well as the use of an American minesweeper vessel to help clear the area of Houthi mines, a senior UAE official told CNN.
A US official confirmed the request for the minesweeper had been received and that it had been rejected.
The coalition had sought the minesweeper due to the Houthis' decision to mine the waters near Hodeidah, an action that the UAE official said had prevented the coalition from taking the port.
The UAE official did say the coalition is waiting for a minesweeper from France to clear the mines.
The Emirati official said the request had been rejected within the last 24 hours, saying that while the US did not give a reason for the rejection the official believed the request was denied because of congressional opposition over concerns about potential civilian casualties.
In recent days several members of Congress have publicly criticized the Saudi-led effort to capture Hodeidah, which is seen as a vital lifeline for supplies for war-torn Yemen. Some estimates have said the operation could put hundreds of thousands of lives at risk.
But while the request for US military assistance was denied, the Emirati official said the Trump administration has publicly and privately said it supports the operation, as long as the coalition coordinates with the United Nations, takes efforts to protect civilians and continues to deliver humanitarian aid.
"They did not encourage us, but did not discourage us," the official said. "Not giving us military assistance is not the same as telling us not to do it."
The official said the coalition has rolled out a plan for humanitarian aid, including plans to establish a shipping lane to Hodeidah from Abu Dhabi and Jizan, a southern city in Saudi Arabia. The plan includes delivery of food, medical supplies, economic aid and electricity. Several ships in the area are stocked with aid and once the airport is open, that aid will be delivered by air.
The Pentagon would not say Thursday whether it had rejected the request for support but called Hodeidah "critical to the delivery of humanitarian assistance to relieve the suffering of the Yemeni people."
"We are not directly supporting the coalition offensive on the port of Hodeidah," Pentagon spokesman Maj. Adrian Rankine-Galloway told CNN.
The US military has for some time been providing aerial refueling support to coalition warplanes and has provided the coalition with information to help prevent civilian casualties.
The Saudi-led coalition announced Wednesday the launching of the military operation to capture the last Houthi-controlled port. The UAE official said the operation was part of an effort to break the military stalemate between the coalition and the Houthis, who the US and the coalition view as being armed and backed by Iran.
The internationally recognized government of Yemen -- led by Abdu Rabu Mansour Hadi -- has also signaled its support for the Hodeidah operation.
But the attackers have encountered resistance, with one UAE landing craft catching fire after coming under fire from Houthi defenders, Houthi, Emirati and US officials told CNN. The UAE official said four Emirati soldiers were killed in that attack.
The US has said it supports UN-mediated efforts to resolve the issue.
"Secretary of Defense James Mattis strongly supports the efforts of the new UN special envoy, Martin Griffiths, to bring all sides of the conflict to the negotiating table," Rankine-Galloway, the Pentagon spokesman, told CNN.
The senior UAE official said the coalition gave Griffiths a chance to negotiate with the Houthis and get them to abandon the port but that the Houthis rejected those efforts.