Secretary of State John Kerry on Thursday said the United Nations Security Council must act next week to pass a binding resolution calling for the destruction of Syrian strongman Bashar Assad's chemical weapons stockpile.

“Now the test comes,” Kerry said in a surprise appearance at the State Department briefing room. “The Security Council must be prepared to act next week.”

Kerry’s words come days after he reached an agreement with his Russian counterpart calling on the Assad regime to turn over its chemical weapons to the international community and avoid a threatened U.S. military strike.

In the days since, however, Russian leaders continue to suggest that Syrian anti-government rebels — not Assad — was responsible for an August chemical weapons attack that drew condemnation from the U.S. and its allies.

“Time is short; let’s not spend time debating what we already know,” Kerry said, laying the stage for the critical UN talks next week in New York.

Kerry pointed to a recent UN report, dismissed by the Russians, which strongly suggests that forces loyal to Assad were responsible for the attack which targeted civilians in a rebel-controlled suburb outside of Damascus.

Although the Obama administration has hailed the U.S.-Russian agreement as a way to avert military action in Syria, critics still question Russia’s commitment to de-arming a close ally.

The White House has already signalled it likely won’t ask for the United Nations to approve military force in Syria in the event that Assad doesn’t give up his chemical weapons.

The Obama administration made the concession in the face of stiff opposition from the Russians.

But Obama has also warned that a military strike is on the table if Syria fails to follow through.

The United Nations General Assembly meeting next week could prove critical to Obama’s second term policies in the Middle East.

In addition to Syria, Obama could use the UN meeting to reach out to Iran, following the election of moderate President Hassan Rouhani.

The White House on Thursday signaled that Obama would be open to talks with Rouhani if the nation agrees to drop its pursuit of nuclear weapons.

"The extended hand,” White House press secretary Jay Carney said, “has been there from the moment the president was sworn into office.”

Critics of Obama have questioned if halting his planned strike on Syria after Assad crossed a “red line” by using chemical weapons will embolden Iran, which is seen as a far bigger threat to U.S. interests.

Iran says its nuclear program is for peaceful energy purposes, but the U.S. and international community fear Tehran is developing nuclear weapons.