Tel Aviv, Dec 19 : The mediatory talks between Israel and Hamas initiated by Qatar and Egypt has hit a roadblock as the two warring sides refused to agree to the demands put forward by the each other. The talks have not progressed even after Mossad chief David Barnea met CIA Director William Burns and Qatari Prime Minister Sheikh Mohammed bin Abdulrahman Al Thani in Warsaw on Monday. Sources in the Israeli government told IANS that the militant group has put forward a condition that the Jewish nation's forces should return to preset lines to which the country will not agree. In a statement on Sunday, Hamas had said that would not agree to any hostage release until the Israel army stops its ongoing ground offensive in the Gaza Strip -- a condition that the Israel Defense Forces won't agree to. According to source, Israel however, is open to the idea of the Hamas choosing the hostages to be released from its captivity. During the now-collapsed humanitarian ceasefire in Gaza from November 24 to December 1, Israel had chosen its hostages to be released. The government sources told IANS that further mediatory talks will only commence after the differences put forward by the two sides are addressed properly, with both Qatar and Egypt trying to iron it out. During the humanitarian pause, 86 Israeli and 24 foreign national hostages were released. The Israeli authorities estimate that about 129 people remain captive in Gaza, including foreign nationals. /IANS