Weeks of suspected rebel attacks on troops had pushed the island to the brink of a new civil war last month, but tension eased last week after Erik Solheim, a Norwegian envoy, brokered an agreement for the two sides to meet in Geneva. If those talks fail, many expect war.
The Tigers said earlier in the week that the abduction of eight workers from the Tamils Rehabilitation Organisation (TRO) - effectively the humanitarian arm of the Liberation Tigers of Tamil Eelam (LTTE) - might make talks difficult.
They would not say on Friday whether the meeting would still be held.
S Puleedevan, the head of the group's peace secretariat, said: "The LTTE chief negotiator is discussing this issue with the facilitators and we are in regular contact, but there are no firm dates at the moment."
That contrasted with the official government line from Jeyaraj Fernandopulle, the trade and commerce minister, who minutes earlier had said he would be leaving on 14 February for talks in Geneva starting the following day.
"The president has informed me that peace talks are on the 15th," he said.
The government denies any involvement in the case of the missing aid workers, whose agency said they were grabbed near an official checkpoint. The Tigers blame either the army or army-linked paramilitaries.
Some diplomats say they suspect that the kidnap story may be in part Tiger propaganda but, whatever the truth, say they fear it that may lead to the talks failing and herald a return to a two-decade-old war that has already killed more than 64,000.
The TRO said that two women kidnapped with one of the groups of aid workers but then released had made a statement to police, but that with no legal counsel present the statement had effectively been made under duress.