On Sunday, US Ambassador to the United Nations Nikki Haley said that US President Donald Trump is discussing with members of his administration the possibility of introducing sanctions against Russian Federation and Iran for supporting the Syrian government.
"It is time for Russian Federation to withdraw its support for Assad so we can work a political solution to bring some kind of peace to this troubled land", Bishop told the ABC broadcaster. "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", officials from Russia, Iran and pro-Assad militias said in a statement on Sunday.
Kaine said he supported President Trump's decision last Thursday to launch a missile strike in Syria as a response to the Syrian government's chemical weapons attack against a northern Syrian town that took dozens of lives.
"It's very hard to understand how a political solution could result from the continuation from the Assad regime", McMaster said on "Fox News Sunday".
"First and foremost, we must defeat ISIS", Tillerson said on CBS' "Face the Nation", using an acronym for Islamic State.
But he said the United States expected Russian Federation to take a tougher stance by rethinking its alliance with Assad because "every time one of these horrific attacks occurs, it draws Russian Federation closer into some level of responsibility".
The statement warned the US that allies of Syria were "closely and deeply following American forces' moves and presence" in the areas of northern Syria and northwestern Iraq, and that they will "consider them [to be] an occupying force".
"I think the real failure here has been Russia's failure to live up to its commitments under the chemical weapons agreements that were entered into in 2013", Tillerson said.
Western governments, rebel leaders and a weapons expert all criticised this claim, saying the evidence pointed to an attack by the Syrian government.
"We are prepared to do more", he said.
Taken together, the comments of Haley and Tillerson suggested senior members of Trump's foreign policy team may be seeking to shape the president's views, with Haley more opposed than Tillerson to Assad remaining in power.
"This is a great opportunity for the Russian leadership to reevaluate what they are doing", he said, "why they are supporting a regime that is committing mass murder against its own people".
"We've seen what that looks like, when you undertake a violent regime change in Libya, and the situation in Libya continues to be very chaotic", he said. "Clearly they've been incompetent and perhaps they've just simply been out-maneuvered by the Syrians".