A team of US arms experts will accompany Secretary of State John Kerry to Geneva to meet with Russian counterparts for high-stakes talks on Syria's chemical weapons, a US official said Wednesday.

Kerry is set to meet his Russian counterpart Sergei Lavrov first on Thursday, but officials said the talks could stretch into Saturday.

Russia said Wednesday it had given the US its plan to put Syria's chemical weapons under international control amid hopes of a diplomatic solution to the crisis triggered by an alleged gas attack near Damascus last month.

The move came a day after threatened US-led strikes against President Bashar al-Assad's regime were put on hold in response to Russia's offer to oversee Syria giving up its arsenal.

Kerry and Lavrov are expected to closely examine the Russian proposal, but State Department spokeswoman Jen Psaki said that so far Moscow had "put forward ideas" rather than a "lengthy package," adding there were still "components that need to be worked out."

"We certainly know that there are challenges. There are potentially a large amount of chemical weapons in Syria's stockpile," Psaki said.

So the United States and Russia would have to "figure out how to make the destruction effort logistically and technically possible."

Kerry will also meet with the UN-Arab League special envoy on Syria, Lakhdar Brahimi, during his visit to Geneva, Psaki added.

President Barack Obama has dispatched Kerry to Geneva, after Syrian officials appeared to welcome the Russian proposal to rein in its chemical weapons.

Acknowledging for the first time the existence of Syria's chemical weapons, Syrian Foreign Minister Walid al-Muallem said Damascus would be prepared to join the international convention on banning such arms.

"Over the last 48 hours... the credible threat of US military action has created a diplomatic opportunity to remove the threat of chemical weapons in Syria without the use of force," Psaki said.

Kerry was to head to Geneva later Tuesday "not only to meet with Foreign Minister Lavrov, but we will also be bringing a team of experts to meet with their team of experts," she told reporters.

Washington wanted to "hear from the Russians about the modalities of their ideas that they have put forward and to assess whether they meet our requirements" for the disposal of Syria's chemical weapons, she said.

"Our goal here is to test the seriousness of this proposal, to talk about the specifics of how this would get done, what are the mechanics of identifying, verifying, securing and ultimately destroying the chemical weapons."

But she stressed the path forward would require "willingness from both sides."

There were currently no plans for Kerry to meet with Muallem, she added.