The deal to exchange hundreds of Palestinian prisoners for captured Israeli soldier Gilad Shalit is facing obstacles caused by "Israeli obstinacy," Khaled Mashaal, the leader of Palestinian Islamist movement Hamas, said on Tuesday, according to dpa. "This topic is still under negotiation, and there are obstacles due to Israeli obstinacy," the Damascus-based leader told a news conference after a meeting with Yemeni President Ali Abdullah Saleh during a two-day visit to Sana"a. "Hamas is holding on to its demands for the release of our prisoners and setting the leadership and major figures free," Mashaal said. Israel and Hamas have held indirect talks mediated by Egypt and Germany to reach a prisoner swap deal, under which the Israeli soldier would be freed in exchange for hundreds of Palestinian prisoners jailed in Israel. Shalit was captured in a Hamas cross-border raid from the Gaza Strip three years ago. Mashaal said the "ultra-extremist policies" adopted by the government of Israeli Prime Minister Benjamin Netanyahu regarding the Jewish settlements have been "blocking horizons of resolution" in the conflict. He also criticized "weakness" the United States and the international community in not putting greater pressure on Israel.