Statements about supporting the territorial integrity of Syria "are only words that, apparently, cover plans for reformatting the Middle East and plans for dividing Syria into parts," Lavrov said, according to the Associated Press.
Lavrov met with his counterparts, Iranian FM Javad Zarif and Turkish FM Mevlut Cavusoglu, at a summit for Syria and the Iranian nuclear deal in Moscow on Saturday.
The three vowed to continue to work through the Astana process to find a solution for the Syrian conflict and increase humanitarian aid.
"We will ensure that this aid is provided in the most effective way. We will be cooperating with the government, the opposition and of course with our counterparts at the United Nations, the International Red Cross, the Syrian Red Crescent and other international organizations," Lavrov said.
Russia and Iran have backed Baath Party leader and Syrian President Bashar al-Assad through the conflict.
Turkey, however, did an about face and supports regime change in Damascus. However, Ankara disagrees with international coalition support for the Kurdish YPG (People's Protection Units), who have been described as the most effective counter-ISIS forces in Syria.
"Today, the US supports terrorist organizations, and this has to stop," Cavusoglu said.
The US-led Global Coalition to Defeat ISIS has helped to establish civil and military councils in liberated cities — mostly east of the Euphrates with the exception of Manbij. They did not interfere in Turkey's assault and subsequent occupation of the Kurdish canton of Afrin in the far northwest governorate of Aleppo.
The United States has repeatedly said it will remain in Syria until ISIS is defeated.
US President Donald Trump has announced troop withdrawals "soon," but his generals haven't confirmed such orders.
US policy in Syria is for the country to hold “free and fair elections” backed by the United Nations.
Syria was established under French Mandate in 1924. It is a diverse country with Arabs, Kurds, Druze, Alawites, Turkmen, various Christian ethnicities, Turkmen, Yezidis, and other ethno-religious components.
