By Warren Strobel
GENEVA (Reuters) - The United States will insist that Syria take rapid steps to show it is serious about abandoning its vast chemical arsenal, senior U.S. officials said, as Secretary of State John Kerry arrived in Geneva on Thursday for talks with Russian Foreign Minister Sergei Lavrov.
Among the first steps Washington wants, one U.S. official said, is for the government of Bashar al-Assad to quickly make a complete, public declaration of its chemical weapons stockpiles as a prelude to inspecting and neutralizing them.
The aim, the official said, "is to see if there's reality here, or not" in a Russian proposal for Syria to give up its chemical weapons. The United States and its allies say the Damascus government used those weapons in deadly attacks outside the Syrian capital on August 21.
Kerry plans to hold at least two days of talks with Lavrov on the plan, floated by Moscow this week and rapidly accepted by Syrian President Bashar al-Assad's government.
The hope, the officials said, is that Kerry and Lavrov can agree on a blueprint for Syrian disarmament whose main points would be adopted in a U.N. Security Council resolution.
Kerry also will meet on Thursday with Lakhdar Brahimi, the U.N.-Arab League envoy for Syria.
The U.S. secretary of state is accompanied by a large delegation of State and Pentagon nonproliferation experts, and a representative of the U.S. intelligence community, in anticipation of detailed, arms control-style talks on how to turn the Russian offer into a concrete disarmament plan.
Kerry's delegation will present the Russians with U.S. intelligence agencies' assessment of the scope of Syria's chemical weapons infrastructure, believed to be among the world's largest, said the official, who briefed reporters on condition of anonymity.
U.S. President Barack Obama, whose efforts to gain public and congressional backing for U.S. military action in Syria have made no headway, cautiously embraced Russia's diplomatic proposal in a prime-time White House speech on Tuesday.
But U.S. officials acknowledge it is far from clear, for both political and logistical reasons, whether an agreement can be struck.
Kerry himself was almost dismissive in an apparently off-hand comment earlier this week on the possibility that Syria might agree to disarm its chemical weapons.
Underscoring the gap that remains between Russia and the United States, Russian President Vladimir Putin in an op-ed in the New York Times reiterated Moscow's view that it was Syrian rebels, not the government of President Bashar al-Assad, who used poison gas on August 21.
The desire to avoid a prolonged diplomatic process that would ease international pressure on Assad has prompted Kerry and his team to insist on quick signs of good faith from the Syrian leader.
"What we are seeking ... is the rapid removal of the repeated use of chemical weapons by the regime. And that means a rapid beginning to international control" over the stockpiles, said a second senior official traveling with Kerry.
Weapons declarations like the one the United States wants from Syria have long been a feature of arms control agreements, going back to Cold War efforts to limit nuclear weapons.
Syria this week acknowledged, apparently for the first time, that it has chemical weapons, but has blamed the August 21 attack on the rebels.
Inspecting, securing and neutralizing them in the midst of a civil war that has killed over 100,000 people will be a stiff challenge, officials acknowledge.
"It is doable, but difficult and complicated," the first official said.
The second official said Syria's chemical weapons stocks are "much larger" than those held by Libya, which voluntarily agreed to abandon them under former dictator Muammar Gaddafi. But they are "much smaller" than the arsenals held by the United States and Soviet Union during the Cold War, before both sides agreed to eliminate them.
The U.S. and Russian delegations are also expected to discuss the question of how to provide security for any weapons inspectors who would go to Syria.
Asked whether U.S. specialists might join any inspection teams in Syria, the first official said: "We're not ruling anything in or out."
(Editing by Ralph Boulton)