Prime Minister Binyamin Netanyahu, who has held his tongue for months in the face of Turkish Prime Minister Recep Tayyip Erdogan’s serial remarks against Israel, jabbed back Thursday, labeling Erdogan’s characterization of Zionism as a crime against humanity “sinister and mendacious.”Breaking with its practice of not responding to such tongue-lashings in the hope of not exacerbating its shaky ties with Ankara, the Prime Minister’s Office issued a statement saying Netanyahu strongly condemned Erdogan’s comments and “comparison of Zionism and fascism.”Reuters contributed to this report.Speaking Wednesday before a Vienna forum of the Alliance of Civilizations – a UN framework for West-Islam dialogue – the Turkish prime minister said, “It is necessary that we must consider – just like Zionism, or anti-Semitism, or fascism – Islamophobia as a crime against humanity.”In his response, Netanyahu said, “This is a sinister and mendacious statement the likes of which we thought had disappeared from the world.”Israeli officials said Thursday they did not know whether US Secretary of State John Kerry would raise the issue during his visit to Turkey on Friday. Kerry is on a 10-day, nine-country trip. It has been widely expected that improving ties with Israel would be on the agenda of his talks in Ankara, since this is something the US has consistently been pushing.The White House condemned Erdogan's remarks on Thursday."We reject Prime Minister Erdogan's characterization of Zionism as a crime against humanity, which is offensive and wrong," White House spokesman Tommy Vietor said in a statement."We encourage people of all faiths, cultures, and ideas to denounce hateful actions and to overcome the differences of our times," he said.In January, following the circulation of a 2010 video showing Egyptian President Mohamed Morsi calling Jews bloodsuckers and the descendants of apes and pigs, a visiting senatorial delegation immediately challenged him over that comment.Foreign Ministry spokesman Yigal Palmor said Erdogan’s comments were “hollow words that only reflect ignorance.”“Zionism is the national movement of the Jewish people, and to deny any people their right to self-determination and to their national movement is absurd,” he said. “We will not dignify such nonsense with any future comment.”The Geneva-based UN Watch, which first flagged and circulated the Turkish leader’s speech, expressed shock at the comments. The group also urged UN Secretary-General Ban Ki-moon – who was present on the stage when Erdogan made the remarks, and stayed silent – “to speak out and condemn the speech.”“We remind secretary-general Ban Ki-moon that his predecessor Kofi Annan recognized that the UN’s 1975 Zionismis- racism resolution was an expression of anti-Semitism, and he welcomed its repeal,” UN Watch said.It also called on Erdogan to apologize.The group said the Turkish leader had misused a global podium to “incite hatred” and issue “Ahmadinejad-style pronouncements.”The American Jewish Committee, Anti- Defamation League and B’nai B’rith all denounced the remarks.One government official pointed out that the comments had come during a speech that was not devoted to Israel, and reflected Erdogan’s mind-set that it was just natural to include Zionism in a list of the world’s evils.“He was just stating what for him is the obvious,” he said.Nevertheless, the official continued, Israel needs to keep trying to improve ties with Ankara “against all odds.”“Stabilizing ties with Turkey is strategically important for us, and we must keep trying,” he said.Erdogan made the comments despite messages Jerusalem had sent Ankara over the last few weeks that it was interested in creating a more “positive dynamic” in the badly strained relationship so the two countries could work together to further common interests.The content of the messages was that it was important for Israel and Turkey to “get more positive vectors” into their relationship.In the same vein, National Security Adviser Ya’acov Amidror reportedly met with the director-general of the Turkish Foreign Ministry three weeks ago in Rome.