Iranian President Mahmoud Ahmadinejad arrived in Ecuador Thursday on the last leg of a Latin American tour aimed at marshaling support for his country's tense nuclear stand-off with the West.

Ahmadinejad was welcomed by Foreign Minister Rafael Patino after landing at an airbase in the southwestern city of Guayaquil on a flight from Cuba, before heading to the capital Quito for talks with President Rafael Correa.

He arrived in Ecuador amid deep fury in Tehran over Wednesday's killing of an Iranian nuclear scientist, with the government demanding strong UN Security Council condemnation and saying it had evidence unnamed "foreign quarters" were behind it.

The Islamic Republic has pointed the finger at both Israel and the United States, but Washington said it had nothing to do with the deadly car-bombing.

Amid escalating Western pressure to stop alleged efforts by Iran to acquire a nuclear weapons capability, US President Barack Obama and Israeli Prime Minister Benjamin Netanyahu spoke by phone Thursday to discuss the stand-off.

And a senior Russian security official warned of the "real danger" of a US military strike against Iran and possible Western intervention in Syria.

"There is a likelihood of military escalation of the conflict, and Israel is pushing the Americans towards it," Russian Security Council secretary Nikolai Patrushev said in an interview with the Kommersant daily.

"There is a real danger of a US military strike on Iran," he added, saying that strife-torn Syria, which has refused to break its ties with Tehran, could also be a target for Western intervention.

The United States and its allies have accused Iran of trying to develop nuclear weapons under the cover of its uranium enrichment program, charges denied by Tehran.

Last week, Washington warned Latin American countries against deepening their ties with Iran.

"As the regime feels increasing pressure, it is desperate for friends and flailing around in interesting places to find new friends," State Department spokeswoman Victoria Nuland said of Ahmadinejad's trip.

Ahmadinejad will hold talks later Thursday with the speaker of Ecuador's Legislative Assembly, Fernando Cordero, wrapping up his official engagements on a tour that took him previously to Venezuela, Nicaragua and Cuba.

All four countries have frosty ties with the United States, and their leaders have in the past four years made numerous Tehran visits to build up diplomatic and business links while relations with Washington have worsened.

Iran and Ecuador are both members of the Organization of the Petroleum Exporting Countries (OPEC), and the Correa administration recently spoke out in defense of Tehran's right to develop nuclear energy for peaceful purposes.

In Havana Wednesday, Ahmadinejad also won backing from Cuban President Raul Castro for his country's right to the peaceful use of nuclear energy. Iran insists its nuclear program is not aimed at building atomic weapons.

During his brief visit, the Iranian leader met with Castro as well as his 85-year-old elder brother, revolutionary icon Fidel Castro.