The joint airstrikes came under the pretext of punishing the Syrian government for the alleged use of chemical weapons in an attack on the rebel-held town of Douma, east of Damascus on April 7.
Its foreign ministry said: "We welcome this operation which has eased humanity's conscience in the face of the attack in Douma".
He added: "Could not have had a better result.
Mission Accomplished!" His choice of words recalled a similar claim associated with President George W. Bush following the US -led invasion of Iraq.
Bush, in October 2003, disavowed any connection with the "Mission Accomplished" message.
Asked about the air strikes launched by the United States, the United Kingdom and France on Syria following its suspected use of chemical weapons on civilians, MOFA spokesman Andrew Lee (李憲章) said the Republic of China (Taiwan) has always respected and protected human rights and democracy.
That sends a clear message, according the Syrian representative to the United Nations, that there is no interest in a "transparent investigation".
The Syrian state TV reported that air strikes targeted Damascus and surrounding areas.
"This is a very focused strike for one objective to make sure that countries around the world will not use weapons of mass destruction on a regular basis", he said.
Trump said Washington is prepared to "sustain" pressure on Assad until he ends what the president called a criminal pattern of killing his own people with internationally banned chemical weapons.
The three allies used ships, a submarine and warplanes to launch a barrage of 105 guided missiles towards three chemical weapons facilities in Syria, officials said, including a research centre on the outskirts of Damascus.
A "number of missiles" targeted a scientific research center in Barzeh, near Damascus, and destroyed a building housing an education center and labs and caused other damage, the military said.
The Russian military said the missiles were fired from United States ships in the Red Sea as well as from tactical aircraft above the Mediterranean and by U.S. strategic bombers from near the Al-Tanf base. Syria has denied the accusation.
US officials said, however, that the operation was effective in sending a message to the Assad regime about the use of chemical weapons and damaged the nation's chemical capabilities. He said the US knew of no civilians killed by allied missiles. "The US - the possessor of the biggest arsenal of chemical weapons - has no moral right to blame other countries".
Mattis said the assault was a "one-time shot, " so long as Assad does not repeat his use of chemical weapons.
The US-led missile strikes in Syria appear to have been carefully calculated to minimise any further escalation in the Syrian war, while going as far as possible to prevent any further chemical attacks on civilians.
Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, said the USA did not coordinate targets with or notify the Russian government of the strikes, beyond normal airspace "de-confliction" communications.
- During telephone conversations on Saturday afternoon Theresa May, Donald Trump and Emmanuel Macron agreed the military strikes in Syria "had been a success". He criticized the US and its allies for launching the strike without waiting for worldwide inspectors to visit the area.
May seemed determined to resist calls for a retrospective vote on her actions, saying only that Parliament "will get an opportunity to question me" after she has made a statement on the attacks on Monday.
Turkey on Saturday welcomed Western strikes targeting Syrian President Bashar al-Assad's regime as an "appropriate response" in retaliation for a suspected chemical attack that left dozens dead. It said that "all responsibility" rests with Washington, London and Paris.