JERUSALEM: The U.S. military's top general conducted an intense string of closed-door talks with Israeli leaders Friday, amid apparent disagreements between the two countries over how to respond to Iran's disputed nuclear program.

The chairman of the U.S. Joint Chiefs of Staff, Army Gen. Martin Dempsey, and Israeli leaders kept silent about the exact content of their discussions. Dempsey was expected to urge Israel not to rush to attack Iran at a time when the U.S. is trying to rally additional global support to pressure Tehran through sanctions to dial back its nuclear program.

Dempsey met Israeli Prime Minister Benjamin Netanyahu, who has been warning about the dangers of the Iranian nuclear program for more than a decade.

Netanyahu told Dempsey the U.S. should ratchet up sanctions against Iran to ones that would target its central bank and oil exports, the Israeli news site YNet reported. It quoted Netanyahu as saying such measures must be imposed immediately.

Following Dempsey's departure Friday evening, his spokesman, Col. David Lapan, said the meetings "served to advance a common understanding of the regional security environment."

At the start of talks with Israeli Defense Minister Ehud Barak, Dempsey said the U.S. and Israel "have many interests in common in the region in this very dynamic time, and the more we can continue to engage each other, the better off we'll all be."

"There is never a dull moment, that I can promise you," Barak replied, in comments released by Barak's office.

Israel believes Iran is close to completing the technology to produce an atomic weapon. Tehran insists its nuclear program is for peaceful purposes.

Israel has said it prefers employing international diplomacy to solve the problem, but it has not taken the option of a military strike off the table.

Israel considers Iran an existential threat because of its nuclear program, missile development, support of radical anti-Israel forces in Lebanon and Gaza and frequent references by its president to the destruction of the Jewish state.

In an interview published Friday in the Israeli daily Maariv, Israel's recently retired military intelligence chief Amos Yadlin, said the U.S. and Israel now agree that Iran is deliberately working slowly toward nuclear weapons, to minimize international diplomatic pressure and sanctions.

The U.S. and Israel differ about what would be considered unacceptable Iranian behavior that would require a military strike, the former chief claimed.

"While Israel defines the red line as Iran's ability and potential for a breakthrough, the Americans draw the red line a lot farther away," said Yadlin, who stepped down as intelligence chief in late 2010.

He said the Iranian nuclear program was Israel's "only existential threat," noting that in addition to the possibility of a nuclear attack from Iran, its possession of nuclear weapons would spark a regional arms race.

"In that situation, in a nuclear neighborhood, the chance grows that a nuclear weapon could slip into the hands of terrorists," Yadlin said.

Gen. Dempsey also met with Israel's military chief of staff, Lt. Gen. Benny Gantz, and President Shimon Peres.

"I am sure that in this fight (against Iran) we will emerge victorious," Peres said to Dempsey, in comments provided by the president's office. He called Iran a "center of world terror."

Dempsey told reporters he "couldn't agree more" with Peres' "characterization of the common challenge we face."

In between the meetings, Dempsey visited Yad Vashem, Israel's Holocaust memorial and museum. He wrote in its guest book, "We are committed to ensuring that such a human tragedy (as the Holocaust) never happens again." He added, "God bless the victims and protect Israel."

In the past, Netanyahu has sharply criticized Iranian president Mahmoud Ahmadinejad's denial of the Holocaust and has drawn parallels between the world's treatment of Iran today and its failure to act against Nazi Germany in time to save European Jewry.