DUBAI, United Arab Emirates (AP) - The Saudi-led coalition fighting in Yemen announced late Tuesday that it will observe a unilateral cease-fire in the yearslong war, a move it said is aimed at facilitating political negotiations in the kingdom that Yemen's Houthi rebels are boycotting.

The coalition said it would cease hostilities in the brutal war starting at 6 a.m. Wednesday seeking to create a fertile environment for political talks and to jumpstart peacemaking efforts during the holy Muslim month of Ramadan.

However, the announcement raised immediate doubts because there no rebels are present at the Gulf Arab summit about the war in Riyadh. Other unilateral cease-fires announced by the coalition over the past two years have swiftly collapsed.

The Iran-backed Houthis are skipping the summit, called by the Saudi-based Gulf Cooperation Council, because it's taking place in Saudi Arabia, their adversary in the conflict.

The United Nations, diplomats and others had been pushing for a cease-fire to mark the Muslim holy month of Ramadan. Ramadan is likely to start this weekend, depending on the sighting of the new crescent moon.

The GCC, which is a six-nation club including Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates, began the talks Tuesday in Riyadh. The summit is expected to continue through April 7.

On Monday, the GCC Secretary-General Nayef al-Hajraf held talks with British Ambassador to Yemen Richard Oppenheim and Yemeni officials allied with its internationally recognized but exiled government.

Those talks saw al-Hajraf, a Kuwaiti politician, discuss “efforts to stop the war and ways to achieve comprehensive peace to alleviate the human suffering witnessed by Yemeni people,” according to the state-run Saudi Press Agency.

Al-Hajraf attended the World Government Summit in Dubai on Tuesday, but didn't speak about Yemen at his appearance. He declined to answer any questions from an Associated Press journalist as he hurried out of the building, saying: “I have a flight to catch.”

Hours later, the GCC issued a statement quoting al-Hajraf calling on all sides in the war to halt fighting, while again asking the Houthis to take part in the negotiations.

The Houthis have rejected the summit because of its venue in Saudi Arabia, as well as over the continuing closure of Sanaa's airport and restrictions on the country's ports by the Saudi-led coalition that is waging war on the Houthis.

The rebels, who over the weekend attacked an oil depot in the Saudi city of Jiddah ahead of a Formula One race there, have called for the talks to be held in a “neutral” country.

“The Saudi regime must prove its seriousness towards peace ... by responding to a cease-fire, lifting the siege and expelling foreign forces from our country,” Houthi spokesman Mohammad Abdul-Salam wrote on Twitter. “Then peace will come and it is time to talk about political solutions in a calm atmosphere away from any military or humanitarian pressure.”

However, a Geneva-based rights group focused on Yemen, SAM, accused the Houthis of arresting three Yemeni civil rights activists in Ibb province who planned to attend the Riyadh talks. The Houthis did not respond to questions about the arrests.

Iran's Foreign Ministry spokesman, Saeed Khatibzadeh, supported the Houthi position in a statement Tuesday. He also noted Ramadan was soon and said a possible prisoner swap could help ease tensions.

“The plan proposed by Sanaa in good faith carries a strong message suggesting robust determination to end the war, lift the cruel blockade on people and resolve the Yemen crisis through political means,” Khatibzadeh said.

U.S. Secretary of State Antony Blinken spoke late Monday with Saudi Foreign Minister Prince Faisal bin Farhan. The State Department said the two “discussed support for the U.N.'s proposal for a Ramadan truce in Yemen and efforts to launch a new, more inclusive and comprehensive peace process.”

U.S. Special Envoy for Yemen Tim Lenderking traveled to Riyadh to take part in the talks.

The U.S. under President Joe Biden has pulled back from the Saudi campaign while still supplying the kingdom new air defense missiles.

Yemen's war began in September 2014, when the Houthis swept into the capital, Sanaa, from their northwestern stronghold in the Arab world's poorest country. The Houthis then pushed into exile the government of President Abed Rabbo Mansour Hadi, elected in 2012 as the sole candidate after the long rule of Ali Abdullah Saleh.

A Saudi-led coalition, including the UAE, entered the war in March 2015 to try and restore Hadi's government to power. But the war stretched into long bloody years, pushing Yemen to the brink of famine.

More than 150,000 people have been killed in the warfare, according to the Armed Conflict Location and Event Data Project. Those include both fighters and civilians; the most-recent figure for the civilian death toll in Yemen's conflict stands at 14,500.

Also, Saudi airstrikes have killed hundreds of civilians and targeted the country's infrastructure. The Houthis have used child soldiers and indiscriminately laid landmines across the country.

Meanwhile, gunmen shot and killed a security officer in Yemen's southern port city of Aden on Tuesday, security officials said, speaking on condition of anonymity as they were not authorized to brief journalists.

They identified the slain officer as Capt. Karam al-Mashraqi, with the UAE-backed Security Belt militia. Al-Mashraqi was the second senior security official killed this month in Aden, the seat of Hadi's government.

No one immediately claimed responsibility for the killing.

Associated Press writers Samy Magdy in Cairo and Ahmed al-Haj in Sanaa, Yemen, contributed to this report.