A Syrian political opposition group has welcomed a US strike on a government-controlled airbase, hailing Washington's direct military involvement in Syria's conflict as an "opportunity to end" the country's long-running civil war.

The US strike on the Shayrat airfield in Homs province on Friday followed international outrage this week over a suspected chemical attack that killed dozens of civilians in the rebel-held town of Khan Sheikhoun, in northwestern Syria.

"We welcome these strikes," Najib Ghadbian, special representative of the Syrian National Coalition to the United States and the United Nations, told Al Jazeera.

"They are first good steps but we would like them to be part of a bigger strategy that would put an end to the mass killing, an end to impunity and eventually we hope that they will lead to a kind of a political transition [in Syria]."

The strikes, launched from two warships in the Mediterranean Sea, marked the first direct military action the US has taken against Syrian President Bashar al-Assad's forces in the six-year war.

READ MORE: Syria's civil war explained

Ghadbian hailed what he described as a change of policy by the new US administration under President Donald Trump.

"What was lacking in the whole thing was a US leadership to counterbalance the two powers that were providing support to Assad: Russia and Iran," Ghabdian said.

"This could really be the opportunity to end the war - the previous [US] administration, by taking away the military option, emboldened both Russia and Iran. I think this has ended today."

Talal Barazi, the governor of Syria's Homs province, where the Shayrat airfield is based, said the US strike will not affect the Syrian government or its ability to fight "terrorists".

"We are not surprised today to see the [terrorists'] supporting parties interfering directly after the failure of terrorists in targeting Syria," he told local media.

"We will not be surprised to see the Americans playing a direct role on the ground to support its means everywhere."

The Syrian opposition has long criticised the US for failing to protect rebel-held areas from government air strikes, demanding the creation of a no-fly zone or the provision of anti-aircraft weapons to rebel groups.

Several leaders of armed opposition groups demanded the US do more to hinder the Syrian army's abilities.

"One airbase is not enough. There are 26 airbases that target civilians," tweeted Mohammad Alloush, a senior rebel official.

The Free Syrian Army (FSA), a loose alliance of rebel groups that includes factions that have received military support from the United States, called the US strike the "correct starting point" for finding a "just political solution" to the war

"We view that the responsibility of the United States is still great, and does not stop with this operation," it added in a statement, warning that the Damascus government and its allies could commit "acts of revenge" against civilians.