Trump administration officials on Sunday blamed Russian inaction for enabling a deadly poison gas attack against Syrian civilians last week as Secretary of State Rex Tillerson prepared to explain to Moscow a USA retaliatory missile strike.
"It just - if you look at his actions, if you look at the situation, it's going to be hard to see a government that's peaceful and stable with Assad".
Meanwhile, US Secretary of State Rex Tillerson accused Russian Federation of "failing" to "live up to its commitments under the chemical weapons agreements" in relation to the current situation in Syria.
McMaster told Fox News Sunday host Chris Wallace the "president acted decisively" and that while the strike wasn't meant to take out all of Syria's capabilities, "it was a strong signal that the USA will not stand idly by".
Appearing on CBS' Face the Nation, Mr Tillerson said, "The Russians have played now for some time the role of playing cover for Bashar al-Assad's behaviour". "We've already, I think, issued some very strong statements", Tillerson said.
McCain also said he doesn't agree with Tillerson's stance that the U.S.
But asked about the possibility of further intervention, the secretary of state said Washington's "first priority" in Syria was to defeat Islamic State terror group, also known as Daesh.
"Moscow needs a dialogue with London not more than it (Britain) needs it (Russia)", the Foreign Ministry said.
'Russia has strategic interests in Syria, we recognise that, but we need to be working with Russian Federation to counter terrorism and resolve the bloody conflict that has been raging between the Assad regime and opposition forces for almost six years now, ' she said.
"I think the president has authorization to use force", he said.
The chemical weapons attack in Syria that triggered retaliatory American airstrikes hasn't shifted USA priorities toward ousting Syrian President Bashar Assad, top Trump administration officials said.
"The failure related to the recent strike and the recent bad chemical weapons attack in large measure is a failure on Russia's part to achieve its commitment to the global community", he added. Reluctant to put significant troops on the ground in Syria, the US for years has struggled to prevent Assad from strengthening his hold on power.
When asked about Washington's anti-Russia sanctions, the US Secretary of State said "there is no reason to be lifting sanctions". "And saying we are only going after chemical weapons areas ignores the enormity of the problem. From now on, we will respond with force to any aggressor or any breach of red lines from whoever it is, and America knows our ability to respond well".
Meanwhile, US national security adviser Lieutenant-General H R McMaster described the US' goals to defeat IS as well as ousting Mr Assad as somewhat "simultaneous".