Secretary of State John F. Kerry and his Russian counterpart, Sergei Lavrov, agreed to meet in Geneva on Thursday to discuss a Russian proposal for international monitoring and eventual destruction of Syria’s chemical weapons, after a day of rapid-fire ex­changes threatened to derail the nascent initiative.

After near-constant consultations through Monday night into the morning, the United States, France and Britain agreed on the need to establish a legally binding chemical inspection regime backed by the authorization to use force if Syria did not comply with its terms.

By mid-morning, Russia had rejected a proposed U.N. resolution, announced by French Foreign Minister Laurent Fabius, and called an emergency Security Council meeting. Lavrov called the threat of military action “unacceptable,” and Russian President Vladmir Putin said a weapons deal would work only if the United States and others “tell us they’re giving up their plan to use force against Syria.”

After an afternoon telephone conversation between Kerry and Lavrov, the Russians dropped their demand for the emergency meeting and instead agreed that Kerry and Lavrov should talk face to face.

The purpose, a senior State Department official said, is to make sure that what Russia has in mind for Syria’s weapons is comprehensive and verifiable in the midst of a protracted civil war, and to make clear that the United States and its partners insist that the proposal includes consequences if Syria does not comply.

See all six of Obama’s interviews about Syria.

“We’re waiting for that proposal,” a senior administration official said, “but we’re not waiting long. We will take a hard look at it, but it has to be swift, it has to be real, and it has to be verifiable. . . . If the U.N. Security Council seeks to be the vehicle to make it happen, well, then, it can’t be a debating society.”

Just a day after Russia made the surprise weapons proposal and Syria immediately announced its agreement, the Western partners remained wary that it was a ploy designed to head off President Obama’s plan to launch a U.S. military strike. Kerry and other senior administration officials continued previously scheduled congressional briefings to build support for a what it has been called a “limited” attack to punish Syria for using chemical weapons outside Damascus last month, killing more than 1,400 people.

The U.S.-backed Syrian Opposition Coalition was unequivocal in its assessment, calling the initiative a strategy to stall for time and an inadequate response to a chemical attack that had already taken place.

“Crimes against humanity cannot be absolved through political concessions, or surrendering the weapons used to commit them,” the coalition said in a statement.

Although Syria is believed to have large stockpiles of chemical weapons, including mustard gas, sarin and other nerve agents, its government has never explicitly acknowledged possessing them. In a CBS interview last weekend, Syrian President Bashar al-Assad denied that any government chemical attack had taken place. He refused to confirm the existence of the stockpiles and accused the opposition of gassing his soldiers.

But in an interview Tuesday with Lebanese media, Syrian Foreign Minister Walid al-Moualem said that his government would provide “information about our chemical weapons,” according to Russia’s state-funded RT television network.“We will open our storage sites and cease production. We intend to give up chemical weapons altogether.”

Moualem said Syria “fully supports” the Russian initiative and intends “to join the Chemical Weapons Convention” that renounces all chemical use.

The text of a proposed U.N. resolution was outlined Tuesday morning in Paris by Fabius, the French foreign minister. The resolution would also authorize an investigation by the International Criminal Court into war crimes perpetrated by the Assad government, according to a diplomat familiar with the text.

In addition to Lavrov’s rejection of U.N. authorization of the use of force, a Russian Foreign Ministry statement indicated that Moscow does not want a Security Council resolution at all. Instead, the statement said, Russia envisions a statement by the council’s president — who rotates and is now an Australian representative — that would “welcome” the plan to monitor and ultimately destroy Syria’s chemical weapons and call on “interested parties” to carry out the plan.

In London, British Prime Minister David Cameron told members of Parliament that the bare-bones Russian proposal was “definitely worth exploring” but that it must be “tested out properly” to ensure it wasn’t a “ruse.” Any Security Council resolution, he said, must include “a proper timetable, process and consequences if it’s not done.”

Just two weeks ago, Cameron appeared to become peripheral to international action on Syria, after Parliament rejected his proposal to join the United States in a military strike. But the new turn of events appeared to place him back in the mix as a close U.S. partner, along with France.

In addition to the calls made by Kerry, the White House said that Obama spoke separately Tuesday morning with Cameron and French President François Hollande.

“They agreed to work closely together, and in consultation with Russia and China, to explore seriously the viability of the Russian proposal to put all Syrian chemical weapons and related materials fully under international control in order to ensure their verifiable and enforceable destruction,” White House press secretary Jay Carney said in a statement. Their discussions, Carney said, will include “elements of a potential U.N. Security Council resolution.”

In Washington, Kerry told a House committee that the proposal “is the ideal way” to take chemical weapons away from Assad’s forces. But he warned that the administration would not tolerate “delay” or “avoidance.”

The Arab League, which the United States has looked toward for support for a military strike on Syria, welcomed the Russian proposal Tuesday. Speaking at its organization’s Cairo headquarters, Arab League head Nabil Elaraby told reporters that it had always been in favor of a “political solution” to the Syrian crisis, the Associated Press reported, saying that Elaraby added, “Thank God.”

Iran, among Assad’s strongest supporters, also voiced support for the plan. Quoting Hossein Amir-Abdollahian, Iran’s deputy foreign minister for Arab and African affairs, the Iranian news agency IRNA said that Damascus and Tehran welcomed the proposal as a way of preparing the ground for resolving the Syrian crisis through political means.

The agency also said the deputy minister expected the entire region to be cleared of weapons of mass destruction, noting that Israel’s undeclared nuclear weapons should also be “taken into consideration.”

DeYoung reported from Washington.