By Dominique Heckels, Washington Producer
The US and its allies must add momentum to Donald Trump's Syrian airstrikes by rebuilding the Free Syrian Army, setting up a safe zone and forcing President Assad out, John McCain has told ITV News.
The Republican senator, who has been a leading critic of the Trump administration, said he fully supported the president's air strike directive as he discussed the damage it had done on the Assad regime.
The senator accused Syrian President Bashar al-Assad and his Russian allies of being "slaughterers" - pointing to the use of "precision weapons in Aleppo to strike hospitals".
"This is the kind of people they are," Mr McCain said. "There's only one thing that they understand and that is, that unless things change, the United States of America is perfectly capable of enacting further punishment for their heinous crimes."
Senator McCain said if the Syrian regime carries out more chemical attacks on civilians, there will be a proportionate response, and is convinced the world will be on side of the United States of America.
Mr Trump's ordered missile strike, less than 72 hours after Tuesday's suspected chemical attack, caused an implosion both on the airfield and also on the somewhat intangible realm of international relations.
The UK, Saudi Arabia, China, Turkey and South Korea all backed the strikes. Unsurprisingly, Russia condemned the strikes - as has North Korea, calling them "aggressive".
In an emergency UN Security Council meeting on Friday, Nikki Haley, US Ambassador to the UN, said the US was "fully justified" in striking the Syrian airfield.
"The United States took a very measured step," she added. "We are prepared to do more but we hope that will not be necessary."
Her comments came little more than a week after she had revealed US policy in Syria was no longer focused on removing Assad from power.
Whether Friday morning's airstrikes were a one-off attack by the US on Assad’s regime or part of a multifaceted strategy to eradicate the Syrian president from power is still unclear.
Senator McCain is convinced Mr Trump’s next move should be to build on this first attack, saying it has encouraged US allies and countries in the region.
He said the job now is to "reconstitute the free Syrian army, set up a safe zone and the eventual departure of Bashar al-Assad".
Mr Trump's next move remains indistinct - as is the vote the UN Security Council will come to within the next few weeks on the situation in Syria.
The UN decision appears all the more pressing amid reports on Friday and Saturday that new airstrikes had been carried out targeting the same town in Syria that was hit by suspected chemical weapons earlier this week. The perpetrator(s) of the strikes is yet to be confirmed.
With waters becoming ever murkier, the one thing of which Mr McCain seems certain is his trust in Trump after his frustration with President Obama.
"The president did the right thing, sent the right signal and frankly we've got to understand it's the beginning," he said.
"It's not the end of what has been going on for the past eight years and a failure of American leadership.
"I think in the eyes of the National Security Council team this was a response which, not just as far as amount of damage is concerned, sent a strong signal that the US will no longer tolerate these violations of international law and these horrendous actions that kill innocent women and children. We can't stand by and watch that happen.”