Updated

A Shiite rebel leader in Yemen vowed to not surrender Sunday amid Saudi-led airstrikes in a rambling speech that rejected U.N. efforts to halt violence there, even as the political party of the country's former leader welcomed international efforts for a cease-fire.

The speech by rebel leader Abdul-Malek al-Houthi, his first since the Saudi campaign began, offered signs of cracks appearing in his alliance with Yemen's one-time President Ali Abdullah Saleh. However, his speech signaled no sign of his rebels backing down from their offensive after earlier seizing the capital, Sanaa, and forcing President Abed Rabbo Mansour Hadi into exile.

"The great Yemeni people will never surrender and never be subjugated," al-Houthi said.

Saudi Arabia and allied countries began their airstrike campaign on March 26, hoping to roll back the Houthi advance, which began in September. Western governments and Sunni Arab countries accuse the Houthis, who largely are Zayidi Shiites, of receiving military support from Iran. Iran and the rebels deny that, though the Islamic Republic publicly has sent humanitarian aid into the country.

As of Tuesday, the strikes have killed hundreds of Houthi fighters and at least 364 civilians, the U.N. has said.

As al-Houthi blamed Saudi Arabia, the United States and Israel for orchestrating the campaign against his forces, the political party of Yemen's former longtime autocrat said it welcomed a U.N. resolution calling for a cease-fire in the country. In a statement on its website, Saleh's General People's Congress said that it would "respond positively" to the U.N. Security Council resolution issued last week.

Pro-Saleh forces have been fighting alongside the Houthis.

The U.N. resolution demands that all Yemeni parties, especially the Houthis, end violence and return swiftly to U.N.-led peace talks aimed at a political transition. It makes no mention of the Saudi-led airstrikes targeting the rebels and pro-Saleh forces.

Meanwhile Sunday, pro-Hadi forces regained control of part of the Aden coastline that had been held by the Houthis and their allies, security officials said. The gained positions allow them to attack the rebel-held airport and cut off supplies to anti-Hadi forces, they said.

Rebel forces also made another push to take the Dar Saad area, just north of Aden, but failed, the officials added, speaking on condition of anonymity because they were not authorized to brief journalists.

In Amman, the United Nations said Saudi Arabia had agreed to fund completely a $273.7 million appeal for emergency aid to avoid a humanitarian catastrophe inside Yemen.

Purnima Kahsyap, humanitarian coordinator for the U.N. aid effort in Yemen, said that the U.N. was thankful to Saudi Arabia for covering the entire appeal cost, but urged all other partners to continue to provide assistance.

The U.N. and aid partners have repeatedly called for pauses in the fighting so aid can be delivered.

In a statement Sunday, aid group Oxfam said an airstrike by the Saudi-led coalition hit one of its storage facilities in Saada governorate in northern Yemen. "This is an absolute outrage, particularly when one considers that we have shared detailed information with the coalition on the locations of our offices and storage facilities," country director Grace Ommer said. The statement said no one was killed.