By Stephen Brown

BERLIN (Reuters) - Iran's Foreign Minister Ali Akbar Salehi said on Monday he saw U.S. Vice-President Joe Biden's offer this weekend of bilateral dialogue between their two countries as a sign of a change in approach to Iran by the U.S. administration.

"As I have said yesterday, I am optimistic, I feel this new administration is really this time seeking to at least divert from its previous traditional approach vis-a-vis my country," Salehi told the German Council on Foreign Relations in Berlin.

Tehran insists its nuclear program is peaceful but the West suspects it is intended to give Iran the capability to build a nuclear bomb.

Salehi, who attended the Munich Security Conference at the weekend where Biden made the offer, said in Berlin that it was still very difficult for Tehran and Washington to trust each other. "How do we trust again this new gesture?" he said.

Salehi said he hoped Barack Obama would keep what he said was a promise by the U.S. president to "walk away from wars...and approaches that bring destruction, killings, bloodshed". He did not elaborate.

Negotiations between Iran and six major world powers - Russia, China, the United States, Britain, France and Germany - over Tehran's nuclear activities have been deadlocked since a meeting last June.

European Union officials have accused Iran of dragging its feet in weeks of haggling over the date and venue for new talks.

The EU said this weekend it had proposed talks in the week of February 24 which could happen in Kazakhstan. Salehi called this "good news" - but the EU says Iran has not yet accepted.

"BORING" NUKES

"I think it is about time both sides really get into engagement because confrontation certainly is not the way," Salehi said in Berlin, referring to the United States.

"And another thing: this issue of the nuclear file is becoming boring," added Salehi, a physicist by training who once headed the Iranian atomic energy agency and represented his country at the International Atomic Energy Agency (IAEA).

Salehi faced tough questioning on Tehran's support for Syrian President Bashar al-Assad in a civil war in which about 60,000 people have died. Iran and Russia, Assad's main backers, met the Syrian opposition leader this weekend but Tehran seems to remain convinced that Assad must not be ejected from power.

He denied Iran was sending solders to help Assad, saying: "The army of Syria is big enough, they do not need fighters from outside."

Iran was only sending economic assistance, food and fuel, said the minister, adding that the Damascus government and opposition should sit down, agree a ceasefire and call free elections in which he said Assad should be free to take part.

Iranian opposition members protested at the venue and one managed to sneak in among the diplomats, interrupting the minister with shouts of "He's a murderer!"

Salehi was asked by an Israeli newspaper correspondent if he would visit the Holocaust monument in Berlin to 6 million Jews killed by the Nazis, and what he thought of President Mahmoud Ahmadinejad's repeated denials that the Holocaust took place.

"Any holocaust is a human tragedy," Salehi replied, refusing to be drawn deeper on the subject.

(Reporting by Stephen Brown; Editing by Gareth Jones and Pravin Char)