One official said the task is "doable but difficult and complicated."
The official said the U.S. is looking for signs of Russian seriousness and thinks it will know in a relatively short time if the Russians are trying to stall. Another official described the ideas that the Russians have presented so far as "an opening position" that needs a lot of work and input from technical experts. The U.S. team includes officials who worked on inspection and removal of unconventional weapons from Libya after 2003 and in Iraq after the first Gulf War.
The officials, who spoke on condition of anonymity because they were not authorized to speak publically on the sensitive negotiations, said the teams that eventually go into Syria to do the work would have to have an international mix, as would their security.
In an opinion piece published Thursday in The New York Times, Russian President Vladimir Putin wrote, "The United States, Russia and all members of the international community must take advantage of the Syrian government's willingness to place its chemical arsenal under international control for subsequent destruction."
Putin urged the U.S. not to launch a military strike on Syria, saying, "It is alarming that military intervention in internal conflicts in foreign countries has become commonplace for the United States."
Kerry planned to meet Thursday with Lakhdar Brahimi, the U.N.-Arab League envoy for Syria, before sitting down with Russian Foreign Minister Sergey Lavrov.
The hastily arranged meeting in Geneva comes as the White House tries to pin success or failure of the diplomatic track on Russia's willingness to take a tough line with its ally Syria. Syrian rebels, however, are disappointed at best in President Barack Obama's decision to forgo a military strike in favor of an agreement to take access to chemical weapons away from President Bashar Assad.
At the same time, the CIA has been delivering light machine guns and other small arms to Syrian rebels for several weeks, following Obama's decision to arm the rebels.
The agency has also arranged for the Syrian opposition to receive anti-tank weaponry like rocket-propelled grenades through a third party, presumably one of the Gulf countries that has been arming the rebels, a senior U.S. intelligence official and two former intelligence officials said Thursday. They spoke on condition of anonymity because they were not authorized to discuss the classified program publicly.
The Washington Post and The Wall Street Journal first reported the lethal aid.
Top rebel commander Gen. Salim Idris told National Public Radio on Thursday that rebels had received no such aid from the U.S. The CIA declined to comment.
The officials said the aid has been arriving for more than a month, much of it delivered through a third party, which could explain why the rebel commander Idris does not believe the U.S. directly delivered the aid. The officials said the aid is delivered to commanders who have been vetted by the CIA, and the path of the weaponry is tracked through trusted parties within the country though eventually, once they're in the hands of fighters, the U.S. loses sight of where the weapons go.
The rebels continue to request sophisticated anti-aircraft weaponry to take out the Syrian regime's helicopters, but the officials said neither the U.S. nor Syria's neighboring countries, like Jordan or Israel, wants the rebels to have weaponry that may fall into the hands of the al-Qaida-linked rebel group al-Nusra, or captured by Hezbollah fighters who are bolstering the Syrian army's effort.
The CIA program is classified as covert, which means it would be briefed to Congress's intelligence committees but not its defense committees. That explains why some senior lawmakers on the defense committees have complained the lethal aid was not arriving, two of the officials said.
In meetings planned for later Thursday and again Friday with Lavrov, Kerry will prod Moscow to put forward a credible and verifiable plan to inventory, quarantine and destroy Syria's chemical weapons stocks, according to U.S. officials.
Kerry is accompanied by American chemical weapons experts to look at and possibly expand on Russian ideas for the complex task of safely dealing with the vast stockpiles in the midst of a brutal and unpredictable conflict. Russian technical experts will join Lavrov in the meetings.
The U.S. is hoping that an acceptable agreement with the Russians can be part of a binding new U.N. Security Council resolution being negotiated that would hold Syria accountable for using chemical weapons. Russia, however, has long opposed U.N. action on Syria, vetoed three earlier resolutions, blocked numerous, less severe condemnations and has not indicated it is willing to go along with one now.
American ships in the Mediterranean Sea remained ready to strike Syria if ordered, Navy Secretary Ray Mabus said. Syrian rebels appeared skeptical that U.S. forces would be put to use, saying the Americans have repeatedly reneged on promises to assist their rebellion. They pointed to Obama's statement in June that he would provide lethal aid to the rebels.
On Capitol Hill, action on any congressional resolution authorizing U.S. military intervention in Syria was on hold, even an alternative that would have reflected Russia's diplomatic offer. Senators instead debated an energy bill.
"The whole terrain has changed," Sen. Dick Durbin, D-Ill., told reporters after a meeting of Democrats on the Senate Foreign Relations Committee. "We want to make sure we do nothing that's going to derail what's going on."
That didn't stop Republicans from announcing their opposition to Obama's initial call for military strikes and criticizing the commander in chief. Sen. Deb Fischer, R-Neb., accused the president of engaging in "pinball diplomacy."