UNITED NATIONS — Israel’s defense minister, Ehud Barak, will tell Secretary General Ban today that the violations of a U.N. Security Council resolution that ended the Lebanon War, which strengthen Iran’s allies in Lebanon, present “real and serious danger” for Israel, according to an aide.

The increasing firepower of Hezbollah and other issues involving a growing anxiety in Israel over Iran’s regional influence — including how to deal with Tehran’s nuclear menace — were at the top of Mr. Barak’s agenda in meetings with top Bush administration officials yesterday and Monday in Washington. Mr. Barak is expected in New York today.

“The amount of missiles possessed by Hezbollah was doubled and even tripled, and their range was extended significantly” since the 34-day war in Lebanon two years ago, which ended only when the Security Council passed resolution 1701, Mr. Barak told Vice President Cheney on Monday, according to a defense ministry statement. Resolution 1701 envisioned the disarming of all Lebanese militias, including Hezbollah, as well as a weapons-free area in southern Lebanon. Hezbollah’s violations “verge on changing Lebanon’s precarious political equilibrium, which Israel sees as a real and serious danger,” Mr. Barak was quoted as saying.

“We have to admit that it simply isn’t working,” an aide to Mr. Barak, who spoke yesterday on condition of anonymity, said, speaking of resolution 1701. The aide also said that Israel has no intention of handing another victory to Hezbollah by negotiating over the fate of Shaba Farms, an area now claimed by Lebanon but that Israel believes is used as pretext for keeping Hezbollah armed.

Hezbollah’s increased power in Lebanon and its threat to Israel are seen in the region as part of Iran’s effort to use anti-Israel sentiments to further its sphere of influence. “Israel has become politically dead after its humiliating defeat” in the 2006 war, which was “a great victory for Lebanon and for the world of Islam,” Iranian parliament speaker Ali Larijani yesterday told a gathering in Tehran of the Non-Aligned Movement.

Mr. Barak signed an agreement with Defense Secretary Gates to upgrade missile-defense systems, which will “significantly improve Israel’s ability to deal with the threat of long-range missiles,” he told Israeli reporters yesterday. In confronting the Iran’s nuclear issue “all options” should be on the table, Mr. Barak added. Pentagon spokesman Geoff Morrell said Monday that “the Israelis are keenly aware that we believe the best possible avenue of dissuading the Iranians from pursuing nuclear weapons is through economic and political pressures.”