When asked whether the United States is considering any sanctions against Russia for its support Damascvus in Eastern Ghouta, Nauert said Thursday, "We never forecast sanctions."
"But I can tell you that there are a lot of options that there are now being considered," the spokesperson added.
Nauert also noted that the State Department is also engaged in other diplomatic efforts to apply pressure on the Syrian government.
"We are engaging in talks with the Russians in Geneva, the State Department is. We are investigating various mechanisms that would hold Russia and the Syrian regime accountable for using chemical weapons on its own people," she explained.
On Saturday, the UN Security Council unanimously adopted Resolution 2401 that urges parties to the conflict to immediately stop all hostilities and adhere to a long-term humanitarian pause across Syria in order to ensure the unhindered delivery of humanitarian aid, as well as medical evacuation of those injured.
In turn, Russian Defense Minister Sergei Shoigu announced on Monday that a new daily humanitarian pause in Eastern Ghouta would start on Tuesday on 09:00 and last until 14:00 local time (07:00-12:00 GMT).
In addition, the United States views Russia's call for a humanitarian corridor in Syria's Eastern Ghouta as a joke, Heather Nauert said.
“The idea that Russia is calling for a so-called humanitarian corridor, I want to be clear is a joke,” Nauert said on Thursday. “This idea of a so-called humanitarian corridor which is a narrow little banner, that if you look at the video that you see on TV, people are not using that.”
However, Washington's accusations against Moscow of alleged non-compliance with its obligations in Syria are aimed at preserving the extremist enclave in Eastern Ghouta, Russian Embassy in the United States said Friday.
"The sweeping propaganda campaign launched by Washington, consisting of accusations that Russia had failed to comply with its obligations in Syria, suggests that it is not a matter of concern for lives of peaceful Syrians, but a cold-blooded political forethought: to keep the extremist enclave in a suburb of the Syrian capital whatever it takes," the embassy said on Facebook.
Moreover, Russia warns the United States against an attempt to use unsubstantiated accusations of chemical attacks as a pretext for strikes on the Syrian authorities' facilities, the Russian Embassy in the United States said Friday.
Eastern Ghouta, located on the outskirts of Damascus, is one of four Syrian de-escalation zones that were created during the Astana talks on Syrian reconciliation. Russia, Iran and Turkey serving as guarantors of the de-escalation agreements, which do not apply to the Islamic State or al-Qaeda terrorist groups (both banned in Russia) or their affiliates.
Violence has escalated in recent weeks in Eastern Ghouta, where the al-Qaeda-linked Nusra Front has launched daily rocket and mortar attacks on Damascus. Russian officials have blamed Nusra for the escalation in violence.