Syria's foreign minister will address world leaders at the UN today as Russia and the United States continue airstrikes in the war-torn country.
America has accused Russia of "indiscriminate" bombing against the Syrian opposition, but the Kremlin says its aim is the same as that of America - to target terrorist groups.
Russian jets have hit a camp operated by a rebel group trained by American CIA agents, it has been claimed.
The strikes were said to be among 30 conducted by Russian planes in Syria after Vladimir Putin entered the conflict on Wednesday.
Russia maintains that 12 Islamic State targets, including an IS command centre, were hit in the wave of strikes.
But Foreign Minister Sergei Lavrov has now admitted IS is not the only target - and that other anti-Assad groups would be pursued.
"If it looks like a terrorist, if it walks like a terrorist, if it acts like a terrorist, if it fights like a terrorist, it's a terrorist," he told reporters at the UN General Assembly in New York.
"We are going to fight ISIL (IS) and other terrorist groups. This is the same position as the Americans are taking.
"We see eye to eye with the coalition on this one."
Mr Lavrov claimed the Free Syrian Army - which has been supported by the US - was not a target and should be part of a political solution.
Sky News' Foreign Affairs Editor Sam Kiley said this was Russia "reaching out" to the US.
But the Liwa Suqour al Jabal rebel group, which says it received training by CIA agents in Qatar and Saudi Arabia, has apparently been hit in the initial strikes.
The anti-Assad group's leader, Hassan Haj Ali, said its training camp in Idlib province was struck by about 20 missiles in two separate sorties.
Meanwhile, the Kremlin denied reports the attacks had killed at least 36 civilians, including five children.
Russia, which sees the regime of Bashar al Assad as a strategic ally in the Middle East , began strikes after a request from the government in Damascus.
There are currently 32 Russian warplanes based near the Syrian port city of Latakia, guarded by 1,700 Russian marines.
Defence Secretary Ashton Carter accused Russia of "pouring gasoline on the fire" with airstrikes in Syria.
Mr Lavrov's was asked about this comment by reporters in New York.
"We know about many fires gasolined by the Pentagon," he said.
Diplomats from Russia and the US have met for a third time in a week to try to find common ground on Syria.
But the White House said Russia had failed to learn from history if it thought it could impose a military solution on Syria by wiping out all opposition to Mr Assad.
It said: "Russia will be no more successful than the US was in imposing a military solution on Iraq, or Russia was in imposing a military solution on Afghanistan."
The White House added that a military intervention would be "dangerous" for Russia as it would be dragged into what would become an "indefinite" conflict.
Elsewhere, Russia said it would consider any request from Iraq to strike against IS there.
But Mr Lavrov did not comment at the UN on reports of a joint Iran-Syria ground offensive.
Hundreds of Iranian troops have arrived in Syria in the last 10 days.
An estimated 250,000 people have been killed in Syria's four-year civil war between Mr Assad's troops, rebel groups and Islamic State.
A further 11 million have been displaced.