America will never desert the state of Israel, President Bush said last night, sending an unambiguous signal to the ruling mullahs in Iran – who are developing a nuclear weapon capability in the teeth of international pressure – that their threats to destroy Israel will be fiercely resisted.

“America’s commitment to Israel’s security is strong, enduring, and unshakable,” Mr. Bush said in a speech to the American Jewish Committee, which was celebrating its centennial at Washington’s National Building Museum, and while sitting alongside the German chancellor, Angela Merkel.

He said America and Israel were “natural allies and these ties will never be broken.”

In his first major foreign policy speech for some time, Mr. Bush made clear his words were intended to be heeded by the Tehran regime and its president, Mahmoud Ahmadinejad, who declared in October that the Jewish state should be “wiped off the map.”

America would be unflinching in its commitment to defend Israel’s right to exist and to ensure that the mullahs would not gain possession of a nuclear weapon. Iran already has obtained missile technology from the North Korean communists capable of reaching the capitals of Europe.

Mr. Bush said he was concerned by the direction Iran is heading. “We are concerned because the Iranian regime is repressing its people, sponsoring terrorists, destabilizing the region, threatening Israel, and defying the world with its ambitions for nuclear weapons,” he said. “America will continue to rally the world to confront these threats.”

The president also reiterated his determination not to deal with terrorists, including the Palestinian Arab government dominated by the Hamas terrorist group.

“Hamas has made it clear that they do not acknowledge the right of Israel to exist, and I made it clear that so long as that’s their policy we will have no contact with the leaders of Hamas,” he said to enthusiastic applause.

“Hamas must accept the demands of the international community to recognize Israel, disarm and reject terrorism, and stop blocking the path to peace,” he said.

“As you know, I’m a strong believer of democracy and free elections, but that does not mean that we have to support elected officials who are not committed to peace,” he said. “Democratically elected leaders cannot have one foot in the camp of democracy and one foot in the camp of terror.”

Mr. Bush raised the issue of carnage in Darfur. “We must understand that the rape and the murder and the suffering must be stopped,” he said. “And that’s why I believe strongly that we must augment A.U. [African Union] forces with a blue-helmeted U.N. force, with a NATO overlay, so that we send a clear message to the leaders of Sudan: We will not tolerate the genocide taking place in that country.”

Mr. Bush remembered Ariel Sharon, the former prime minister of Israel who remains in a coma. “Ariel Sharon is a friend who remains in our thoughts and prayers,” he said. “He is a man of courage and a man of peace. And so tonight we pray for his recovery and we rededicate ourselves to the cause to which he devoted his life – the peace and the security of Israel.”

The president introduced the German chancellor, Mrs. Merkel, who made history by becoming the first German head of government to address the committee’s annual gathering.

“I know that this is anything but a matter of course for a chancellor of the Federal Republic of Germany to be invited to address you here tonight,” Mrs. Merkel said before pointedly reminding the audience it will soon be the 61st anniversary of the end of World War II when “the world was liberated from the reign of terror imposed by national socialists.”

“It must not be permitted that Iran gets possession of nuclear weapons,” Mrs. Merkel said. “We need to stand together.”