BERLIN (Reuters) -- Israeli Prime Minister Ehud Olmert stumbled into controversy during a visit to Germany on Monday, implying for the first time Israel had nuclear weapons.

Olmert is on a three-day trip to Germany and Italy where aides said he would press Europe to take stronger measures to stop what Israel claims are efforts by Iran to develop nuclear weapons.

Iran has signed the nuclear Non-Proliferation Treaty and its nuclear program is designed solely to generate electricity. All nuclear activities in Iran are strictly monitored by the UN nuclear watchdog.

Israel is widely believed to have the Middle East's only nuclear arsenal, although officials have refused to confirm or deny that in the past.

Olmert appeared to be the first to say otherwise, when in an interview broadcast on German television as he arrived in Berlin for talks with Chancellor Angela Merkel, he was asked if Israel's alleged atomic effort weakened the case against Iran.

"Iran, openly, explicitly and publicly threatens to wipe Israel off the map. Can you say that this is the same level, when they are aspiring to have nuclear weapons, as America, France, Israel, Russia?," Olmert replied.

The subject of Israel's nuclear capability was raised last week by incoming U.S. Defense Secretary Robert Gates, who suggested at a Senate confirmation hearing that Israel had atomic weapons.

Gates said Iran might want an atomic bomb because it is "surrounded by powers with nuclear weapons: Pakistan to their east, the Russians to the north, the Israelis to the west and us in the Persian Gulf".