(CNN) -- The top general in the Yemeni opposition says he rejects a new proposal that would allow the country's embattled President Ali Abdullah Saleh to remain in power until a new leader is found.

"The general public in Yemen is seeking a transfer of power to the vice president," Gen. Ali Mohsen al-Ahmer said in an exclusive interview with CNN. "This is a principle that we must follow because there are agreements that sides have signed and it is compulsory that all sides agree on its specifics; not change its points."

Ahmer, a leading Yemeni military leader who defected to the opposition in March, told CNN that the Yemeni people want full implementation of an agreement written by the Gulf Cooperation Council that would push out Saleh and hold elections for a new government.

Ahmer also called for the United States, the European Union and the GCC to pressure Saleh to step down.

"Our friends the Americans and the Europeans and the British and the GCC and Saudi Arabia are guarantors for its implementation," Ahmer said of the power transfer plan.

Yemen has been consumed by unrest for months as protesters have demanded an end to Saleh's rule. And Ahmer's stance is likely to harden its political stalemate.

Vice President Abdu Rabu Mansoor Hadi is the acting leader of Yemen in the absence of Saleh, who was wounded in a June 3 assassination attempt and is getting treatment in Saudi Arabia.

Saleh has said he intends to return.

Under the Gulf Cooperation Council plan, Saleh would have given up power to a transitional government after 30 days. But in May, after four members of his ruling party signed the deal, he refused -- saying he would not leave the country to sign the deal because he feared a coup, according to a senior official of his ruling General People's Congress party.

According to Ahmer, Hadi can make significant changes in Yemen even though he holds the title of acting president.

Ahmer spoke highly of Hadi, referring to him as "our brother the vice president" and calling him wise. He said "all sides agree on him and all respect him" to head the interim leadership that would oversee elections for a new government.

"In truth, he does not act with full authority as president of the Republic of Yemen, but in the future, he will practice his full authority," Ahmer said.

However, officials loyal to Saleh insist that he has to oversee any transition for it to be legitimate.

In recent weeks, government troops have battled both anti-government tribal forces and Islamic militants, including al Qaeda in the Arabian Peninsula.

Asked what steps are being taken to avoid further escalation of the conflict, Ahmer said the opposition wants the United States to play a role "because they are guarantors in this initiative."

"The people must help with these peaceful demands -- whether friends or neighbors -- to help Yemen pass to safe waters," Ahmer said.

CNN's Greg Botelho and Tom Cohen contributed to this report.