A fiery anti-Israel speech by Iranian leader Ayatollah Ali Khamenei, delivered shortly after a successful Iranian satellite launch, added to growing global tensions Friday, as Israel warned that it might mount a preemptive strike against the Islamic republic’s nuclear facilities despite U.S. objections.

“From now onward, we will support and help any nations, any groups fighting against the Zionist regime across the world, and we are not afraid of declaring this,” Khamenei said during a rare Friday prayer lecture at Tehran University.

“The Zionist regime is a true cancer tumor on this region that should be cut off,” the supreme leader said. “And it definitely will be cut off.”

Most of Khamenei’s rhetoric was not new. But the timing and setting of his speech hardened a standoff that some analysts say has the potential to spark military action. Such a development would disrupt the international coalition that has emerged to confront Iran over its nuclear program, as well as jeopardize oil markets and the fragile global economy.

Khamenei’s speech, which comes ahead of a planned resumption of nuclear talks, exemplified his view of Iran as the flag-bearer in battles against the “arrogant powers,” a term used in Iranian political discourse to describe the United States and its allies.

U.S. and European sanctions, Khamenei said, are actually helping Iran to develop and will never succeed in halting the country’s nuclear enrichment program.

“These sanctions are aimed at making Iran back down, but Iran will not back down,” he said. “These sanctions are aimed at dealing a blow to us, but in fact, they are of benefit to us.”

The supreme leader’s tone Friday differed from that struck recently by President Mahmoud Ahmadinejad, who said last month that Iran is ready for talks with the West. While Khamenei did not mention the upcoming nuclear discussions, he made clear that compromises such as suspending uranium enrichment are not on the table. Iran has the upper hand in its standoff with the West, he said, because its opponents are “fading powers.”

Khamenei also said that Israel has become “weakened and isolated” in the Middle East because of the revolutions — he called them “Islamic awakenings” — that have spread through the region.

He suggested that Iran’s support for the Palestinian militant group Hamas and for Lebanon’s Hezbollah had helped lead to victory in their battles with “the Zionist state,” as Israel is officially called here.

“We got involved in the anti-Israeli issues, which resulted in victory in the 33-day and 22-day wars,” Khamenei said, referring to Israel’s 2006 war with Lebanon and its incursion into the Gaza Strip in late 2008.

An adviser to Khamenei said in a recent interview that despite the divergence in tone, Iran’s leaders see eye to eye when it comes to the West: Iran welcomes dialogue, but don’t expect it to compromise.

“Compare the U.S. to a complaining neighbor, baselessly nagging about everything,” said Mohammad Kazem Anbarlouei, editor in chief of the Resalat state newspaper. “Why would you compromise with such a person? And why should we compromise with the U.S.? They should just leave us alone.”

Khamenei’s speech came hours after Iran’s state-run media reported that the country had launched into space a small satellite carried by a homemade rocket. The launch, which had been planned and announced months ago, is part of a series of festivities celebrating the 33rd anniversary of Iran’s Islamic Revolution, which culminated in the collapse of the monarchy on Feb. 11, 1979.

State-run television reported that the Navid-e Elm-o Sanat (“Good message of science and industry”) microsatellite carries camera and telecommunication devices and was designed and manufactured in Iran.

Ahmadinejad joined the launch remotely via video link and said he was hopeful the launch would “send a signal of more friendship among all human beings,” wire services reported.

Iran’s space program is controversial, as Western nations fear the rockets could be used for regional attacks and — if the country were to produce a nuclear weapon — be fitted with a nuclear warhead. Iran has repeatedly stated that its missile program is for defensive purposes only.

The Navid satellite will orbit Earth at an altitude of up to 234 miles, the Associated Press reported, citing the Islamic Republic News Agency. It is the third small satellite Iran has built and launched in the past few years and the first of three scheduled for launch in early 2012.