Salih Mahmud Leyla/Anadolu Agency/Getty Images(WASHINGTON) — The U.S. government announced Monday that it is suspending all Syrian peace talks with Russia over frustrations with Moscow and its inability to live up to commitments to a cease-fire agreement.

“There is nothing more for the United States and Russia to talk about,” White House spokesman Josh Earnest said Monday of negotiations to end the 5-year Syrian civil war. He called it a “tragic” development that will lead to more loss of life.

The announcement comes two weeks after the most recent attempt at a cease-fire fell apart in dramatic fashion when a humanitarian aid convoy trying to reach besieged areas of rebel-held Aleppo was destroyed by an airstrike.

The U.S. blamed Russia for that attack, and the Russians later suggested it could have been carried out by a U.S. drone, a claim the U.S. military strongly denied. The attack on the aid convoy was followed by a resurgence of airstrikes on Aleppo by Russia and the regime of Syrian President Bashar al-Assad, resulting in some of the deadliest days of the war.

“The United States is suspending its participation in bilateral channels with Russia” that were established to sustain the cease-fire brokered by the U.S., the State Department announced in a statement to the press.

“Russia and the Syrian regime have chosen to pursue a military course … as demonstrated by their intensified attacks against civilian areas, targeting of critical infrastructure such as hospitals, and preventing humanitarian aid from reaching civilians in need, including through the September 19 attack on a humanitarian aid convoy.”

The failed cease-fire was only the most recent time that the U.S. and Russia — each using their influence with the Syrian opposition and President al-Assad’s regime, respectively — have tried to negotiate an end to the Syrian conflict.

We are suspending our participation in bilateral channels w/ Russia that were established to sustain CoH in #Syria: https://t.co/pZ5USDo9Rn

— John Kirby (@statedeptspox) October 3, 2016

Monday’s announcement makes good on Secretary of State John Kerry’s threat last week to end talks with Russia.

Critics slammed Kerry’s warning last week about ending talks with Russia, saying such a step would have no effect and would not stop Russia from carrying out atrocities against Syrian civilians.

Republican Sens. John McCain of Arizona and Lindsey Graham of South Carolina called the nation’s top diplomat “delusional” in a statement laced heavily with sarcasm.

“We can only imagine that having heard the news, Vladimir Putin has called off his bear hunt and is rushing back to the Kremlin to call off Russian airstrikes on hospitals, schools and humanitarian aid convoys around Aleppo,” the statement read. “After all, butchering the Syrian people to save the Assad regime is an important Russian goal. But not if it comes at the unthinkable price of dialogue with Secretary Kerry.”

Had the cease-fire agreement succeeded, the U.S. and Russia would have established a military-intelligence sharing operation aimed at continuing strikes on extremist forces in Syria through a so-called Joint Implementation Center. The State Department said Monday it will withdraw personnel that had been dispatched to the region in anticipation of that mission, but that it will continue to use established military communications channels to avoid conflict with Russia’s own counterterrorism operations.

The decision to end talks comes on the same day Russia announced it will suspend a 16-year-old nuclear weapons control agreement with the U.S.

Russian President Vladimir Putin said Washington’s “unfriendly actions” don’t permit it to continue. That agreement had called on each side to destroy 34 tons of highly enriched weapons-grade plutonium and was seen at the time it was signed as a milestone in the U.S. and Russia’s attempts to reduce their nuclear arsenals after the Cold War arms race.

State Department spokesman Elizabeth Trudeau said Monday that Russia’s suspension of the nuclear agreement and the U.S. calling off talks on Syria are not linked.

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