The rebels' approval came after Norwegian envoy Eric Solheim met the reclusive leader of the rebel Liberation Tigers of Tamil Eelam (LTTE) on Wednesday.
Anton Balasingham, the Tamil Tiger negotiator, said the 2002 ceasefire would be reviewed at the talks.
Solheim met Velupillai Prabhakaran, the LTTE chief, in the rebel-held city of Kilinochchi for about 2 1/2-hours and delivered a message from Mahinda Rajapakse, the Sri Lankan president, who had earlier agreed to resume peace talks that broke down in 2003 over the rebels' sweeping demand for autonomy.
Solheim is expected to meet Rajapakse later on Wednesday after returning to Colombo.
The Tigers want to create a separate homeland for Sri Lanka's 3.2 million Tamils, saying they are discriminated by the majority Sinhalese.