Syria's opposition chief said the international community must not be a bystander to the tragedy of the Syrian people as US and other officials, ministers and military brass gathered for the Munich Security Conference.
US Vice President Joe Biden is due to attend the Munich talks on Saturday.
The freshly re-inaugurated Biden, who on Friday met Chancellor Angela Merkel in Berlin, will in Munich turn his attention to Syria amid fears the conflict may spill over the country's borders.
He is scheduled to meet Russian Foreign Minister Sergei Lavrov and Syrian opposition chief Moaz al-Khatib, and also see UN-Arab League envoy to Syria Lakhdar Brahimi in the southern German city, the White House said.
Outgoing US Secretary of State Hillary Clinton said Iran is stepping up its support for the Syrian regime and that Russia is still arming it, heightening concerns after Damascus threatened to retaliate over a reported Israeli air raid.
"What we would like to see from other countries, including Russia, is an acknowledgement that (Syrian President) Bashar al-Assad must go and that there needs to be a transition within Syria to a new government," said Ben Rhodes, a White House national security adviser.
Khatib on Friday said the international community must not be a "bystander" to the "tragedy" of the Syrian people and reiterated his willingness to talk to the regime.
He joined UN-Arab League envoy Brahimi for late-night panel talks at the Munich Security Conference on Friday.
"As a gesture of good will... we are ready to sit at the negotiating table with the regime but we don't want their hands to be full of blood," Khatib said calling for the release of detainees.
In a surprise move Wednesday, Khatib announced he was ready for dialogue with officials of President Bashar al-Assad's regime subject to conditions, including that "160,000 detainees" are released.
But the opposition Syrian National Coalition said on Thursday that any talks on the country's political future must be about the departure of the regime of Assad.
Asked what Khatib would ask of the US and other governments, he said, speaking through an interpreter, "everything you would provide us with to end the injustice is acceptable".
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He called for "some kind of electronic interference" to prevent the aircraft of the regime shelling the Syrian people.
"If that doesn't work I would demand to destroy the planes and weapons of the Syrian regime because it is just not acceptable for the international community to be a bystander just watching what's happening to the Syrian people," he said.
"We hate war, we do not advocate war... I am warning if this crisis persists it would have grave ramifications on the whole region," he added.
Brahimi for his part called for a "clear decision" from the UN Security Council to set the agenda for a peaceful solution.
Also on the Munich agenda is Iran. Biden, as he began a three-nation European tour on Friday, cautioned Tehran that the opportunity for talks with the West over its contested nuclear programme was not open-ended.
Iranian Foreign Minister Ali Akbar Salehi is expected to attend the Munich talks as well as EU foreign policy chief Catherine Ashton, who represents the so-called P5+1 group of the United States, China, Russia, Britain, France and Germany in talks on Iran's nuclear ambitions.
"President (Barack) Obama has made clear that containment is not an option. We will prevent Iran from getting a nuclear weapon," Germany's Sueddeutsche Zeitung daily quoted Biden as saying.
"We think there is time and space for diplomacy -- accompanied with economic pressure. But this window will not be open for an unlimited time," he said in remarks published in German.
Iran and the six world powers held three rounds of talks last year aimed at easing the standoff over Iran's nuclear activities, which Tehran insists are entirely peaceful, but the last round ended in stalemate in June in Moscow.
Another round of talks was initially expected to be held in December or January but a date and a location have still not been set amid indications that neither side is prepared to substantially change its position.
NATO's plan to withdraw the bulk of its 100,000 combat troops from Afghanistan by the end of 2014 as well as developments in the Muslim and Arab world two years after the Arab Spring revolts are also set to be themes here.
Mali, where French President Francois Hollande will visit on Saturday after France launched an offensive on January 11 against Islamists who had ruled the country's north for months, is also expected to focus minds.
Opening the conference Friday, German Defence Minister Thomas de Maiziere said it was "right and imperative" for France to intervene but military intervention was only the start of a long road towards conflict resolution.