Yemeni President Ali Abdullah Saleh refused to sign the Gulf Cooperation Council (GCC)-brokered deal and warned Sunday against the civil war ignited by the opposition, said Abdu al-Janadi, the deputy information minister.

Official Saba news agency reported that Saleh refused to sign the deal after the opposition rejected going to the Republican Palace to sign it together with him.

In a speech delivered through the state television, he said that "I would sign the Gulf deal only if the opposition's representatives come to the Republican Palace to sign it with me at the same time, because the opposition would be our partner in the power for the next 90 days."

Saleh's decision came after the U.S. stepped up pressure on him to accept the proposal as a step toward ending protests against the regime.

Meanwhile, Saleh's ruling party signed the deal which proposed Saleh leave office within a month, Saba said.

An aide to the president said on condition of anonymity that Saleh attended the signing ceremony, in which five representatives of the ruling party inked the deal, Xinhua reported.

Saleh also warned against a potential civil war if the opposition continued to escalate the four-month-long street protests.

The opposition unilaterally signed the deal on Saturday evening and refused to meet Saleh's condition to go to his presidential palace to sign it again on Sunday.

Saba reported that Saleh had earlier told the GCC official al-Zayani and Western and Gulf ambassadors to Yemen that "the opposition's signing inside closed room will be unacceptable, and such big deal should be held publicly."

Saleh has thwarted the U.S.-backed deal three times since April. If Saleh signs the deal, he should leave office within 30 days in exchange for immunity from prosecution according to the terms of the deal, which also authorized the opposition to form a new government within seven days and arrange for holding presidential and parliamentary elections in 60 days, according to Xinhua.

After Saleh announced his refusal, military tension escalated between the government forces and defected army in the capital Sanaa and other major provinces.

Yemen, a partner in U.S. efforts to root out al-Qaida and its sympathizers in the region, is one of the countries in the Middle East and North Africa that have been shaken by anti-government protests. The Obama administration has condemned the government's violent crackdown, Bloomberg reported.