Secretary of State John Kerry, left, with Sergey V. Lavrov, the Russian foreign minister, in Geneva on Sept. 9, the day they announced the cease-fire. Photo by Kevin Lamarque

The US is not abandoning the pursuit of peace, US Secretary of State John Kerry said in a speech in Brussels. On October 4, one day after the US announced it is halting ceasefire talks with Russia. The US is considering unilateral and multilateral solutions to resolve the Syria crisis. The announcement to suspend negotiations was made only a few hours after Russian President Vladimir Putin ratified Russia’s withdrawal from an agreement with the US on the disposal of plutonium, the material used in some nuclear weapons.

Russian Foreign Minister Sergey Lavrov criticized Washington for not implementing agreements on identifying conflicted forces and transportation routes for humanitarian aid. Spokesman for the Kremlin Dmitry Peskov said Russia will continue to support Syrian armed forces in fighting terrorism. He said the US’s suspension of dialogue with Russia complicates the situation in Syria and Russia will not abandon its anti-terrorism efforts or assistance for the Syrian army. In the latest development, the Russian Defense Ministry confirmed it has deployed S-300 ground-to-air missiles to Syria.

Last month, Russia and the US agreed on a cease fire to facilitate delivery of humanitarian aid in Syria. But the agreement collapsed and they blamed the failure on each other. Russia accused the US of not abiding by its commitment to separate Syrian rebels from terrorist-held areas. While Russia has launched airstrikes and backed the army of President Bashar al-Assad, the US has supported some rebel groups against Assad. American officials warned they would halt negotiations unless Russia halted its airstrikes in Aleppo. Tensions have intensified when a UN humanitarian convoy was bombed on September 19 and the US blamed Russia for the incident.