Palestinian leaders are "very upset" about the kidnapping of two journalists in Gaza and have assured New Zealand diplomats they are doing everything they can to win their release, a New Zealand official said Wednesday. New Zealand's ambassador to Turkey and Israel, Jan Henderson, arrived in Gaza late Tuesday to try to secure the release of New Zealander Olaf Wiig, 36, a cameraman, and American reporter Steve Centanni, 60. Henderson told Associated Press Television News in Gaza she had made contact with diplomatic colleagues and senior Palestinian Authority figures, including in President Mahmoud Abbas' office, immediately after arriving. "They assured me they are doing all they can, they take this matter extremely seriously, and we are looking for a very quick and peaceful resolution to this particular kidnapping," Henderson said. "The Palestinian Authority has offered to cooperate. They are very upset. They have condemned the kidnapping, and they assured me they are doing everything they can for a quick and speedy resolution," she said. Prime Minister Helen Clark has expressed New Zealand's deep concern for Wiig's safety.