The Tamil Tigers say that efforts by the Japanese special envoy to Sri Lanka to end the stalled peace process have not been productive.
Mr Akashi remains optimistic about the peace process
Rebel spokesman SP Thamilselvan said that they still wanted interim self-rule in the north and east.
But he said that the government had indicated that it was not prepared to resume talks on this issue.
Special Envoy Yasushi Akashi met the president, prime minister and senior rebel leaders.
Japan is Sri Lanka's biggest aid donor.
"We shall not accept any alternative proposals, neither will our people accept any alternative proposals discarding the interim self-governing authority," Mr Thamilselvan said after a meeting between the rebels and Mr Akashi in their northern stronghold of Kilinochchi.
"Mr Akashi did not bring any realistic or productive message from the government. The present climate does not facilitate a permanent solution, because the government is making different statements every day," he said.
Mr Akashi for his part stressed the necessity to resume dialogue in the interests of "sustaining the momentum of peace" built over the last two and a half years.
The Tigers say they want interim self rule in the north and east
"I feel there are good prospects for the resumption of talks," he told the Reuters news agency, "and I am glad that the peace process is still intact in the sense that both sides largely adhere to the ceasefire agreement."
Mr Akashi said there were some violations of the agreement, which he deplored.
He arrived in Sri Lanka last week in a bid to persuade the government and the rebels to resume negotiations that broke down in 2003.
Mr Thamilselvan has ended a month-long tour of Europe, in which he tried to acquire support and funding for the rebels.
He warned that if the rebels were not given an interim authority, the Tiger's leader Prabhakaran would have the prerogative to decide what to do next.
An aid package worth $4.5bn was agreed at a donor's conference in Tokyo last year.
But the money is tied to progress in the peace process and so far no funds have been released.
In his last visit in May, Mr Akashi urged both sides to "give and take" in their negotiations.
Sri Lanka's President Chandrika Kumaratunga has invited the rebels to discuss a federal state, but she faces opposition within her own coalition.