He stopped short of accusing Russian Federation of being directly involved in the planning or execution of the attack, saying he had not seen "any hard evidence" to suggest the nation was an accomplice to Syrian President Bashar al-Assad.
The task of military planners was made riskier by the presence of Russian forces in Syria to support Assad's regime in its battle against rebel groups that include Islamic State and al-Qaeda fighters but also some backed by the U.S.
The US fired 59 missiles at a Syrian airbase after the alleged attack.
Russian President Vladimir Putin said he has intelligence that the US has planned similar missile strikes to last week's on a Syrian military base, including plans to strike the capital Damascus, according to comments carried by state media Tuesday.
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".
"Given repeated Russian blocking in the United Nations security council, the USA was determined to act", Fallon said, adding President Trump made "the right call by resorting to careful and narrowly focused military action".
It said the strike was believed to have been carried out by Russian planes, which operate in support of the Syrian government. Russian President Vladimir Putin and Iran's Hassan Rouhani said in a phone call that aggressive US actions against Syria were not permissible and violated worldwide law, the Kremlin said on Sunday.
But instead of regime change, what we should focus on is humanitarian relief ...
Burger King debuts Whopper ad that triggers Google Home devices
Burger King still got some press for its ad, though, so it's probably not too heartbroken about it no longer working as intended. Burger King did not immediately respond to a question asking whether the company had any concerns about angering consumers.
"But neither regime change nor a full-on, unauthorized war against Syria is what we should be doing", Kaine said.
The Syrian foreign minister denied the government's involvement in the Idlib incident, saying it had never nor would it ever use chemical weapons on either civilians or terrorists operating in the country.
Britain has fully supported the USA for its response to the alleged use of chemical weapons in Idlib province of Syria that left almost 80 civilians dead.
As long as Assad stays in power, she said, "there's not any sort of option where a political solution is going to happen".
The U.S. military strategy on Syria has complicated Trump's attempt to warm relations with Russian Federation.
Rouhani also called for an investigation of the suspected chemical weapons attack in Syria last week, and he warned that the U.S. strikes in response risked escalating extremism in the region.
Moscow has further promised to strengthen Syria's anti-aircraft defences and it is shutting down a hotline with the USA created to avoid collisions between their air forces over the country. The responsible approach to take would be for Putin to use his leverage over Assad to remind the Syrian president that he has violated his agreement to destroy all chemical weapons.