The European Union on Saturday welcomed a Russian-U.S. deal to destroy Syria's chemical weapons stockpiles and offered the bloc's help with implementing the agreement.

"I welcome the agreement reached today between the United States and the Russian Federation to ensure the swift and secure destruction of Syria's chemical weapons and program," EU foreign policy chief Catherine Ashton said in a statement.

The United States and Russia on Saturday unveiled an ambitious plan to eliminate Syria's chemical weapons by the middle of next year and left the door open to sanctions if Damascus failed to comply.

The landmark deal was hailed by the West, but rejected by rebels who warn that it would not halt the bloodshed in the conflict which has killed more than 110,000 people and displaced millions in two and a half years.

The United States is setting an unrealistic timeframe for Syria to hand over its chemical weapon arsenal, a senior Russian lawmaker said Saturday as Moscow and Washington entered a third day of talks.

"The demand by the United States to hand over chemical weapons to international control in two or three weeks is simply unprofessional," Alexei Pushkov, the head of the Russian parliament's foreign affairs committee, wrote on Twitter.

The United States concedes that Russia will not allow the U.N. Security Council to authorize military strikes against the Syrian regime, senior White House officials said Friday.

Speaking on condition of anonymity, the officials said a U.N. report due on Monday would strengthen the case that Bashar Assad used chemical weapons against his own people.

World powers are keen on holding a conference on Lebanon given the instability in the region, most notably the Syrian crisis, reported As Safir newspaper on Saturday.

An official Lebanese source said that Russia, China, the United States, and France are in agreement to hold a conference to support Lebanon's stability in order to keep it away from regional conflicts, especially the unrest in Syria.

The United Nations has asked Syria for more information about its application to join the chemical weapons convention, holding up accession, a spokesman said Friday.

Syria applied to the United Nations on Thursday as part of a plan to head off a western military strike against President Bashar Assad over the alleged use of banned chemical arms.

The two men leading diplomatic efforts to end the war in Syria seem like complete opposites. One is a hard-nosed Russian happy to be known as "Mr No", the other an affable, wealthy American, known for his verbosity and occasional gaffes.

Yet despite their different views and backgrounds, U.S. Secretary of State John Kerry and his Russian counterpart Sergei Lavrov seem to have managed in a few short months to develop the working rapport which could prove key in the tough talks ahead.

Iran's new centrist leader Hasan Rowhani on Friday urged Moscow to help solve Tehran's nuclear crisis as he met President Vladimir Putin for a key meeting at a security summit in Kyrgzystan.

"As far as the Iranian nuclear problem is concerned, we would like this problem to be solved as soon as possible within the framework of international norms," Rowhani told Putin in televised remarks translated into Russian in Bishkek.

U.S. Secretary of State John Kerry said Friday he would meet again with his Russian counterpart Sergei Lavrov in New York later this month to try to set a date for a long-delayed peace conference for Syria.

"We both agreed... to meet again in New York around the time of the U.N. General Assembly around the 28th in order to see if it is possible then to find a date for that conference," Kerry told reporters at a joint press briefing in Geneva with Lavrov and the U.N.-Arab League envoy to Syria, Lakhdar Brahimi.

President Vladimir Putin on Friday won the support of Iran and China at a regional summit on Russia's initiative for Syria to hand over its chemical weapons, which he said had proved the "serious intentions" of the Damascus regime.

Putin attended the summit of the Shanghai Cooperation Organization (SCO), a regional security group sometimes seen as an eastern counterweight to NATO, in Kyrgyzstan a day after President Bashar Assad said he supported the Russian plan.