The United Nations Security Council is expected to impose additional sanctions on Iran by the end of March or the beginning of April, American officials told their Israeli counterparts at Thursday's strategic dialogue in Jerusalem.

"The sanctions will not be paralyzing and sweeping, as many would like," a senior Israeli official said. "But they will be firm enough to harm the regime there. Also, a mechanism will be set up to enable additional UN resolutions to be passed swiftly if the Iranians don't change their conduct."

Israel is waging a global diplomatic effort to persuade Security Council members to vote in favor of new sanctions. This week, an Israeli delegation visited Brazil covertly in an effort to persuade its government to support strong measures.

Deputy Foreign Minister Danny Ayalon and U.S. Deputy Secretary of State James Steinberg led the strategic dialogue, whose American participants included senior officials from the White House, the Pentagon and the National Intelligence Council. On the Israeli side, participants included officials from the foreign and defense ministries, the National Security Council and the Israel Defense Forces.

A major part of the dialogue dealt with the diplomatic efforts to stop Iran's nuclear program. The senior Israeli official said the American delegation stressed that it should be possible to pass a resolution imposing a fourth round of sanctions on Iran by the end of March or beginning of April.

The Americans said the Security Council was likely to approve the sanctions by a massive majority that would include Russian support, the Israeli source added. However, they were less optimistic regarding China, which at this stage continues to object to new sanctions.

The United States, Germany, France and Britain are all working to secure majority support for sanctions at the Security Council. At least nine of the council's 15 members must vote in favor of the sanctions for them to pass.

Earlier this week, a delegation of senior Foreign Ministry officials visited Brazil, which objects to imposing further sanctions on Iran. Brazil's foreign minister said this week that his country was interested in mediating between Iran and the International Atomic Energy Agency. Brazilian President Luiz Inacio Lula da Silva is expected to visit Israel next month.

Ayalon plans to visit Nigeria and Gabon, two of Africa's representatives on the Security Council, in a few weeks to try to persuade them to support further sanctions on Iran. Gabon, which will be the rotating Security Council president for March, will play an important role in efforts to advance the sanctions resolution.

An Israeli delegation also traveled to Beijing on Thursday to try to persuade the Chinese to impose more sanctions on Iran. This trip was coordinated with the U.S. administration.

The delegation was headed by Strategic Affairs Minister Moshe Ya'alon and Bank of Israel Governor Stanley Fischer. They are to meet the Chinese president's senior foreign policy adviser and senior Chinese Foreign Ministry officials.

Barak to U.S.: Impose new Iran nuclear sanctions

The U.S. must aid in imposing effective sanctions against Iran's nuclear program, Defense Minister Ehud Barak told U.S. Secretary of Defense Robert Gates during a meeting in Washington D.C. on Thursday.

Barak made the comments during a mostly private session with Gates, joined in parts by Chairman of the U.S. Joint Chiefs of Staff, Admiral Michael Mullen as well as other defense officials, in which participants discussed Iran's alliance with both Syria and Hezbollah following a summit participated by Syrian President Bashar Assad and Iranian President Mahmoud Ahmadinejad in Damascus earlier Thursday.

"It is imperative to impose harsh, paralyzing sanctions on Iran in order to prevent it from any further advancement toward nuclear weapons capability," Barak said in the meeting.

On the subject of Hezbollah, the defense minister said that the Lebanese militant organization was constantly rearming itself, mostly with rockets, which he claims proves the group's sole purpose was "to harm Israeli citizens, which means terror for the sake of terror."

Barak is expected to meet Secretary of State Hillary Clinton on Friday, later meeting with Vice President Joe Biden, who is scheduled to visit Israel on March 8.