Israeli Defence Minister Avigdor Lieberman said Wednesday he was determined to recover the bodies of two soldiers killed in Gaza but insisted he was not keen to negotiate with Hamas.

Oron Shaul, a soldier in the 2014 war in the Gaza Strip, was believed by the Israeli army to have been killed along with Hadar Goldin, and the Palestinian Islamist group Hamas is thought to hold their bodies.

Channel 10 television on Monday quoted him as saying, in two private conversations, that the return of the soldiers' remains was improbable and that he does not want to negotiate with Hamas.

The report triggered an uproar with Goldin's twin brother, Tzour, telling military radio that Lieberman was ignoring "his responsibilities and the army's code of ethics".

Goldin's family later issued a statement denouncing "the abandonment of soldiers on the battlefield by the minister of the defence".

But the ultra-nationalist Lieberman dismissed the accusations against him on Wednesday.

"It is our responsibility to return the prisoners and the remains of soldiers despite difficulties," he said in remarks carried by Israeli media.

He did reiterate however that he was opposed to striking deals with Hamas, like the 2011 agreement which led to the release of soldier Gilad Shalit.

The soldier had been captured by Hamas in 2006 and released in 2011 in exchange for more than 1,000 Palestinian prisoners.

"I was against the Shalit deal and I think I was right, seeing the number of prisoners who have carried out terrorist attacks after being set free," said Lieberman.

"But we have to recover the remains of our soldiers," he added.