The United States special envoy for Syria, James Jeffrey, on Monday accused Russia of not being serious about reaching a political solution to the Syrian conflict.
Jeffrey told reporters that the United States doubts Russia's desire and credibility in finding a comprehensive political solution in Syria, saying that Moscow is the main reason behind the Assad regime remaining in power until now.
The US official said the Turkish-American coordination regarding the Syrian file "has achieved clear positive results in Idlib Governorate".
"The Syrian current economic situation poses a threat to the stability of many countries in the Middle East, including Turkey, Jordan and Israel," he said, adding that what is happening in Lebanon has an impact on Syria and vice versa.
Syria has been ravaged by a civil war since early 2011, when the Assad regime cracked down on pro-democracy protesters.
Hundreds of thousands of people have been killed and more than ten million displaced, according to UN estimates.