China on Monday urged Israel to stop air raids on Gaza and called on both sides for an immediate ceasefire after Israeli Premier Benjamin Netanyahu vowed no let-up against rocket-firing militants.

Israel launched another spate of air strikes earlier Monday, bringing the death toll in Gaza to 20 in three days of tit-for-tat violence that began with Israel's killing of a senior militant on Friday.

Israel will continue air strikes against Gaza "as long as necessary," Prime Minister Benjamin Netanyahu said on Sunday, giving no indication that a ground operation was likely for now.

"We extracted a high price from them and will continue to do so," he said at the start of the weekly cabinet meeting. "We will act as long as necessary."

Defense Minister Ehud Barak warned on Saturday that Israel will continue to hit Palestinians who attack its citizens, after air strikes on Gaza left 15 Palestinians dead.

The United States offered Israel advanced weaponry in return for it committing not to attack Iran's nuclear facilities this year, Israeli daily Maariv reported on Thursday.

Citing unnamed Western diplomats and intelligence sources, the report said that during Prime Minister Benjamin Netanyahu's visit to Washington this week, the U.S. administration offered to supply Israel with advanced bunker-busting bombs and long-range refueling planes.

Israel welcomes the possible resumption of international talks on Iran's nuclear program, but it must prepare for the chance they will fail, Israel's national Security Council chief said Wednesday.

"I am very happy about the resumption of talks between Iran and the big powers, particularly if it results in Iran abandoning its nuclear program. But we must prepare for their failure," Yaakov Amidror told Israeli public radio.

Israel's Benjamin Netanyahu on Tuesday winds up a high-profile U.S. visit focused on Iran's perceived nuclear threat after warning that his country would not live in the "shadow of annihilation."

Netanyahu was to meet with U.S. Secretary of State Hillary Clinton and visit the U.S. Congress a day after keenly-watched talks with President Barack Obama against the backdrop of speculation over a possible Israeli strike on Iran.

Israeli Prime Minister Benjamin Netanyahu arrived in the U.S. capital late Sunday for talks with U.S. President Barack Obama on Iran's nuclear ambitions and how to deal with them.

The plane carrying the Israeli leader and his aides touched down at Andrews Air Force Base outside Washington at about 11:05 pm local time (0405 GMT Monday).

Israel will take any decisions on Iran's nuclear activities as an "independent state," Foreign Minister Avigdor Lieberman said on Sunday, on the eve of a U.S.-Israel summit in Washington.

"Clearly, the United States is the biggest world power and the biggest and most important country that is a friend of Israel, but we are an independent state," Lieberman told Israeli public radio.

Israel's Prime Minister Benjamin Netanyahu said Friday he will not set "red lines" for military action against Iran, insisting he wanted to preserve the Jewish state's freedom to maneuver.

"I have not set down red lines to the United States and will not set down red lines," he said. "I want to reserve Israel's freedom to maneuver in light of threats, every country would demand that."

Israel is keeping the option of military action against Iran open if the international community does not halt its suspected nuclear weapons drive, Foreign Minister Avidgor Lieberman said Friday.

"We are still waiting. We want to believe that the international community will be able to handle this threat... But again we keep all options on the table," Lieberman said when asked about the possibility of a strike on Iran.