(CNN) -- One of the backers of a proposal to end the upheaval in Yemen is walking away over Yemeni President Ali Abdullah Saleh's reluctance to leave the country to sign the pact.

The Persian Gulf emirate of Qatar said the delay is undercutting the deal it helped negotiate between Saleh and opposition leaders through the six-nation Gulf Cooperation Council. As protests against his 32-year rule mount in Yemen, Saleh has said he won't leave the country to sign the deal because he fears a coup, a senior official of his ruling party said last week.

In an announcement carried by the state news agency QNA, Qatar said the decision was made "because of procrastination and delay in signing the agreement proposed in the initiative" and "the continued escalation and confrontations and the loss of wisdom, which is incompatible with the spirit of the initiative."

The agreement states that Saleh will transfer power and leave office within 30 days. It provides immunity for him and those who served in his regime and calls for a unity government to be formed within seven days.

Saleh wants an aide to go Saudi Arabia and sign the deal on his behalf. But that's a no-go for the country's opposition, which is threatening to back out of the accord if Saleh does not personally ink the arrangement.

Yemen is among the Arab countries swept up in protests against longtime rulers since the January revolt that ousted Tunisian strongman Zine El Abedine Ben Ali. The impoverished and unstable nation has been wracked by anti-government protests and clashes between demonstrators and security forces for many weeks.

Witnesses said Yemeni security forces used live ammunition fired on protesters in Sanaa and Taiz on Wednesday, with one activist reporting at least 13 dead. Last week, Yemen's opposition issued a statement warning that "massacres" against street protesters could derail the deal.

The Gulf Cooperation Council is made up of Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates.