Venezuelan President Hugo Chavez and Iran's President Mahmoud Ahmadinejad exchanged warm embraces and signed several trade and political agreements on Monday.

Few details were given to the press - other than that the agreements were meant to expand research in science, nanotechnology, industry and politics.

It was more a display of how they were deepening ties on economic development projects and strengthening their political alliance. Chavez touted ongoing projects such as food processing plants, and tractor and bicycle factories - all of which were built in Venezuela with Iran's help.

He even included pre-recorded segments at the press confence where workers gave viewers tours of corn processing plants and milk treatment plants.

For two of the world's most oil-rich countries though, the projects seemed a bit small scale to be highlighted for the international press.

The visit came amdist rising tensions between Iran and the United States.

Earlier on Monday an Iranian court sentenced a former US marine who holds both Iranian and US citizenship to death after he was convicted of spying.

And it follows threats from Iran to close an important oil shipping channel - the Strait of Hormuz - if the west sanctions its oil exports over its nulear programme.

With world attention on the brewing crisis between Iran and the US, both leaders made a point of criticising the US for its "imperialism."

Lacing barbs with humour, Chavez joked that he and Ahmadinejad were building nuclear weapons in the basement of his presidential palace. And Ahmadinejad said Chavez was the "champion in the fight against imperialism".

On a more serious note Chavez said the war they were fighting was against "poverty, misery, hunger and underdevelopment".

Chavez's rhetoric was wide-ranging - as it usually is. He blamed US imperialism in part for the killing of former Libyan leader Muammar Ghaddafi and for the protests against Bashar Assad's government in Syria.

It was Ahmadinejad's fifth visit to Venezuela and the first stop on a tour of the region that will take him also to Nicaragua, Cuba and Ecuador.

In Nicaragua both he and Chavez will attend re-elected President Daniel Ortega's inauguration and in Cuba Ahmadinejad will meet with Fidel Castro.

As Ahmadinejad meets with longtime foes of the United States, one constant on the trip will likely be continued criticism of the US and its "lackeys", as Chavez calls its allies.