John Kerry, US secretary of state, has addressed the media after arriving in Geneva to meet Russian counterpart Sergey Lavrov as the UN tries to forge an international plan to disarm the Syrian government of its chemical weapons.
Lavrov and Kerry will discuss efforts to agree a UN resolution on the issue, as well as the practicalities of finding, removing and destroying chemical stockpiles during a civil war in which more than 100,000 people have already died.
During a press conference on Wednesday, held shortly after the two men landed in Switzerland, Kerry said that the words of the Syrian regime when it came to handing over chemical weapons were "not enough".
Acknowledging "differences" in view between Russia and the US, Kerry said that the two countries agreed people had been killed on August 21 and that "our job is to eliminate these weapons."
Despite emphasising Obama's wish for a diplomatic solution, Kerry also said "should diplomacy fail, force might be needed" as well as reiterating the US' stance that it was only the "credible threat of force" by them that had lead to the current potential solution.
The diplomats are expected to clash on whether a UN resolution should contain the threat of force - something to which Russia is deeply opposed.
Russian Foreign Minister Sergey Lavrov did not read a statement, instead referring to President Vladimir Putin's opinion piece in the New York Times.
"Our approach is very clear," said Lavrov, "I'm sure you have all read President Putin's [opionion editorial] in the New York Times today."
Al Jazeera's Diplomatic Editor James Bays, reporting from the UN in New York, said he understood both ministers would be accompanied by chemical weapons experts at the meeting in the Swiss city.
The meeting comes a day after the permanent members of the Security Council - the US, UK, China, Russia and France - met to discuss the content of draft resolutions proposed by Russia and France.
France's draft states that Syrian President Bashar al-Assad’s forces should be condemned for their use of chemical weapons on August 21 in Damascus, and threatens force if they do not comply with disarmament.
Russia insists there is no evidence to prove Assad used chemical weapons, and does not want any threat of force in a resolution.
Al Jazeera's Bays said the French resolution was highly contentious, but was "simply the negotiating position of the West, things now move to Geneva".
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Meanwhile, Al Jazeera has been told that UN chemical weapons inspectors will report their findings on the chemical attacks to the secretary-general, Ban Ki-moon, early next week.
Last week, US President Barack Obama threatened military action against Syrian army targets over the chemical attack, and sought congressional support.
On Wednesday, he announced that he had asked the US Congress to postpone a vote on authorising force in order to explore the hastily proposed Russian plan to decommission Assad's chemical weapons.
However, Obama said that he still retained to right to order military strikes, adding: "I've ordered our military to maintain their current posture ... to respond if diplomacy fails."
The Washington Post meanwhile reported on Thursday that CIA operatives had begun funelling weapons and equipment to rebel fighters in the last fortnight, under a plan signed off by the president earlier this year.