"This battle has reached its bitter end," Pathmanathan said in an e-mailed statement. "It is our people who are dying now from bombs, shells, illness, and hunger. We cannot permit any more harm to befall them. We remain with one last choice - to remove the last weak excuse of the enemy for killing our people. We have decided to silence our guns."
Military spokesman Udaya Nanayakkara said troops had found the body of Prabhakaran's eldest son, Charles Anthony, who was said to be the head of the rebels' air wing.
The son - named after a rebel leader who died earlier in the war - was the only one thought to be fighting along with his father.
Separately, the military said special forces found the bodies of the rebels' political wing leader, Balasingham Nadesan, the head of the rebels' peace secretariat, Seevaratnam Puleedevan, and one of the top military leaders, known as Ramesh.
Their bodies were found during mop-up operations in the last remaining Tiger enclave, the Defense Ministry said in a statement.
The military's assertions could not be independently verified as the journalists and observers are barred from the war zone.
In an interview with Britain's Channel 4 news, Pathmanathan said he had spoken with Prabhakaran personally and that the rebel leader remained inside the war zone.
The government forces in recent months ousted the rebels from all their northern strongholds and by yesterday the insurgents were cornered into a stretch of 0.4-square-mile.
The rebels have been fighting since 1983 for a separate state for Sri Lanka's ethnic Tamil minority after years of marginalization at the hands of the Sinhalese majority. More than 70,000 people have been killed in the fighting.
Rights groups have accused the rebels of holding civilians as human shields, and blamed the government for shelling the densely populated area where they sought refuge. Both sides denied the accusations.
