The Kremlin said on Friday such a move would plunge the entire region into complete chaos.

Dozens of State Department officials have signed an internal document that calls for targeted military strikes against the Syrian government, according to the Wall Street Journal.

US Secretary of State John Kerry said on Friday that the internal memo on Syria signed by more than 50 US diplomats is an "important statement" that he would discuss when he gets back to Washington.

"It's an important statement and I respect the process, very, very much. I will ... have a chance to meet with people when I get back," Kerry said during a visit in Copenhagen.

The memo is sharply critical of US policy in Syria, calling for military strikes against the Assad government.

An unnamed US official familiar with the document said the internal cable may be an attempt to shape the foreign policy outlook of the next US administration.

“It is not a secret to us that there are political forces in the US who favor a military solution [to the Syrian crisis]. But this is not our method," Russian Foreign Ministry spokesperson Maria Zakharova said on Friday, Press TV reported.

The United States and its allies have been conducting airstrikes against what are said to be Daesh terrorists inside Syria since September 2014 without any authorization from Damascus or a UN mandate.

The attacks have largely failed to fulfill their declared aim of destroying Daesh but killed civilians and targeted the Syrian infrastructure in many cases.

Washington has consistently refused to join forces with Russia in Syria against Daesh ever since Moscow launched its campaign of airstrikes in September last year.

On Thursday, a senior US defense official accused Russia of carrying out airstrikes in southern Syria against US-backed forces.

The accusation came a day after Kerry said the US was losing patience with Russia over its support for the Syrian government.

"Russia needs to understand that our patience is not infinite. In fact it is very limited with whether or not al-Assad is going to be held accountable," he said.

Responding to those remarks, Russia's Foreign Minister Sergei Lavrov said he believed the US might hope to use al-Qaeda's branch in Syria to unseat President Assad's government.

Lavrov said in St. Petersburg on Thursday that the reluctance of US-backed opposition groups to distance themselves from the Nusra Front has been a major reason behind continuing fighting.

The US could be "playing some kind of game here, and they may want to keep al-Nusra in some form and use it to topple the regime," Lavrov said.