Hamas's senior leader in the Gaza Strip says talks on exchanging captured soldier Gilad Shalit for Palestinian prisoners have frozen.

Mahmoud al-Zahar says the Egyptian-mediated negotiations have broken down because Israel won't meet Hamas demands to release prisoners convicted of murdering Israelis.

Zahar also said Wednesday that the talks have stalled because Israel and Egypt won't open their border crossings with Gaza. Both countries sealed the border after Hamas seized power in Gaza in June 2007.

Hamas wants Israel to free hundreds of Palestinian prisoners in exchange for the soldier. Israel has balked at Hamas' demand to release convicted murderers.

Hamas-led gunmen abducted Shalit in a cross-border raid two years ago.

'Ceasefire giving talks a chance'
Meanwhile, on the Israeli side, Defense Minister Ehud Barak said Tuesday that "the ceasefire gives the negotiations (for Shalit's release) a chance to succeed.

"The ministerial committee is working to relax the criteria (for a prisoner release)," Barak said while touring an IDF artillery base in southern Israel. "This is also important for Shalit's release. Not one day goes by without me thinking about him and without us working on this issue, which is at the core of our responsibility."

The defense minister noted that he was optimistic regarding the resumption of the indirect talks with Hamas, but added that "this time they will be held under embargo, in order to give them a chance to succeed."

Barak visited the base in order to closely monitor the live ammunition training held by the IDF more frequently than in the past. Accompanied by his military secretary, deputy chief of staff and commander of the GOC Army Headquarters, he met with soldiers and commanders and examined new means to be used by the artillery unit.

"We are in the midst of a comprehensive training effort in to have a fit IDF," the defense minister said. "Our aim is to draw lessons from the recent Lebanon war. This huge training effort is led by the chief of staff and backed by me.

"This training session today is the first of its kind in seven years," Barak said. "The goal of this training is to turn the IDF into an army which can meet any challenge facing the State of Israel in the future, to turn it into a victorious army."