Yemeni President Ali Abdullah Saleh strongly criticised his opponents on Tuesday, describing them as "bandits, members of the Taliban and chronic diseases.", dpa reported.
In a televised address to supporters gathered in Sana'a, Saleh vowed to return to Yemen, telling his loyalists, "See you soon in Sana'a."
At least 4,000 representatives from different tribes across Yemen had gathered to take unified steps towards the political stabilization of the country.
Yemen has faced more than six months of political stagnation, after Saleh refused to endorse a Gulf initiative that would have secured a peaceful transfer of power within the framework of the constitution.
In his address, Saleh vowed to stay in office until 2013, and called on his opponents to "go with him to the ballot box."
Saleh's current term ends in two years' time.
"We are not clinging to power, and never said 'power or death'. We were forced to be in power in 2006," he said in a speech from Riyadh, where he has been recovering from wounds sustained during an attack on his palace early June.
The embattled president also described his opponents as "opportunistic" and said they were "trying to take advantage of the youth's revolution."
"I want those who pay money to destroy Yemen to stop," he said, accusing Egypt, China and Russia of financing the Yemeni opposition.
Organisers said their meeting came out of a tribal responsibility to solve the crisis in the country, if political parties were unable to do so.
"The conference will come up with significant proposals that will not prejudice any party," said members of the preparatory committee.
Earlier, the Joint Meeting Parties (JMP), a coalition of five opposition parties, said it would set up an umbrella National Council on August 18, to "lead the revolutionary forces forward to fulfil Yemeni people's aspirations."
Tensions have continued to rise, as government spokesman Abdu al-Janadi dubbed the JMP's announcement a "call for war."
The political dialogue among Yemeni parties, aimed at finding a solution to the unrest, is being led by the Gulf Cooperation Countries (GCC), under the auspices of special UN envoy Jamal Benomar.
After a two-month freeze of the Gulf initiative, Saleh is demanding that two of his rivals, who are also senior members of his Hashid tribe, leave the country as a condition of signing the deal.
Fighting between government security forces and al-Ahmar's supporters broke out in May, when Saleh initially refused to sign the Gulf-brokered deal.
Since mid-February, millions of Yemenis have taken to the streets demanding Saleh's ouster. Around 400 have been killed in government crackdown on demonstrators.