Israeli Prime Minister Ehud Olmert asked Pope Benedict on Wednesday (December 13) to denounce personally a conference in Iran questioning the Holocaust, an Olmert aide said, to reinforce criticism of it by the Vatican. The Israeli leader and the head of the world's 1 billion Roman Catholics spoke for about 40 minutes at the Vatican. Olmert, on a tour of Germany and Italy, renewed a standing invitation for the Pontiff to visit the Holy Land. On Tuesday a toughly worded statement by the Vatican criticised the conference hosted by Iran to question whether Nazi Germany used gas chambers. Iran has been accused of encouraging the denial of the killing of 6 million Jews during World War Two. The Vatican statement said the Holocaust must remain forever a warning to respect the rights of others. Using the Hebrew word for the Holocaust, "Shoah," it expressed "great compassion". The Pope did not give an immediate response to Olmert's invitation but has already told Israeli leaders he would like to visit the Holy Land next year. The first pope to go there was the late John Paul on an historic trip in 2000, after leading the Vatican to forge diplomatic relations with the Jewish state. Olmert and the Pope also discussed outstanding details of a bilateral agreement between the Vatican and Israel regarding property ownership and taxation of the church. The Israeli aide said Benedict also complemented Olmert on "the restraint he has shown" to keep a ceasefire going in Gaza. A Vatican statement said that the Pope, Olmert and Vatican diplomats discussed Middle East prospects, the situation of the Catholic minority in the Middle East and access to Christian sites in the Holy Land over the coming Christmas season. After meeting the Pope and the Vatican secretary of state, cardinal Tarciso Bertone, Olmert met Italian Prime Minister Romano Prodi.