Saudi Arabia has begun direct talks with Houthi rebels over the nearly yearlong war in Yemen, which has become a test of Riyadh’s determination to defend its interests aggressively in the region.

The Saudi-led military coalition and an official for the rebels said on Wednesday the talks were taking place near the Saudi-Yemeni border. But the two sides appeared to differ over the agenda of the negotiations, which began Monday.

“The talks focus on ways of ending the war and starting an immediate cease-fire,” Houthi spokesman Mohammed al-Shire’i said. The coalition indicated only that the negotiations had created a “state of calm” in the border area to allow the delivery of humanitarian aid.

Both sides said they had swapped prisoners, with the coalition adding that the Houthis had released a captured Saudi soldier and freed seven Yemenis detained in a combat zone near the border. It was unclear if the Yemenis were rebels.

Supported by the U.S., a Saudi-led coalition of mostly Sunni Arab states launched an air campaign against the Houthis in March, aiming to quickly unseat the rebels and reinstall President Rabbo Mansour Hadi to power.