Toner made the statement during a question-and-answer session on Twitter, during which he addressed questions about Russia, Syria, Yemen and climate change, among other topics.


“We cooperate when interests coincide, like the Iran deal,” Toner tweeted. “On Syria, a lack of trust led to breakdown in the cessation of hostilities. [We are] working multilaterally to end violence.”


On Thursday, outgoing President Barack Obama addressed US-Russian relations during a trip to Germany. Obama told reporters that it is in the United States’ interest to work cooperatively with Russia to solve the world’s major problems.


Prior to the United States ending bilateral cooperation with Russia over the situation in Syria, US Secretary of State John Kerry and Russian Foreign Minister Sergey Lavrov brokered a cessation of hostilities in the country.


The deal ultimately fell apart due to accusations of violations of the ceasefire by both sides.


The United States and Russia continue to participate in multilateral talks in Geneva aimed at finding a political solution to Syria’s conflict.