"We will reject any new initiative from any country dealing with Yemen's current crisis, "Saleh said.
About 125 people have been killed since a political uprising began in Yemen in February and anti-government protests were expected again Friday in Sanaa and other cities, The National newspaper reported.
Prior to Saleh's statement of rejection, Qatari Prime Minister Sheik Hamad bin Jasem said: "We hope to reach a deal with the Yemeni president to step down," Qatar news agency Thursday.
Both sides were invited to Riyadh, Saudi Arabia, to participate in talks to end the crisis. A date for the talks was not disclosed.
Mohammed Qahtan, a spokesman for Yemen's opposition parties, said a Riyadh deal would be Saleh's last chance for a "safe exit," Gulfnews.com reported Friday.
"The plan calls for the stepping down of [Saleh], guarantee him and his family immunity from prosecution and the formation of a national unity government," Qahtan said. He said the opposition was willing to engage in talks in Riyadh.
The GCC is a political and economic union of the United Arab Emirates, Bahrain, Saudi Arabia, Omar, Qatar and Kuwait.