UK Prime Minister David Cameron stated Friday that there is “limited but growing” evidence that Syrian troops used chemical weapons against rebel fighters in the country.

“It is extremely serious,” Cameron said during an interview with the BBC. “This is a war crime.”

When asked whether the usage of chemical weapons could push the UK to intervene in Syria, Cameron responded that he does not wish to send British troops to the war-torn region.

“I don’t want to see [deployment of troops] and I don’t think that is likely to happen,” Cameron asserted.

Cameron said that the UK should instead work toward strengthening the Syrian opposition in order to put pressure on Assad.

“We need to send a clear message to the Syrian regime about these appalling actions,” he said.

On Thursday, US Defense Secretary Chuck Hagel said that the US intelligence community now believes Syria has likely used chemical weapons on a “small scale” against its civilians.

Hagel added that the use of chemical weapons “violates every convention of warfare.”

The statement came on the heels of a public declaration Tuesday by the Israeli army’s top intelligence analyst that forces loyal to President Assad had used sarin gas against rebel forces and civilians, information which may push the US closer to intervening in the two-year-old conflict.

The White House, however, said the news would not necessarily trigger a response.

No information was made public on what quantity of chemical weapons might have been used in Syria, or when or what casualties might have resulted.

Hagel and President Barack Obama have said in the past that the use of chemical weapons would be a “game-changer” in the US position on intervening in the Syrian civil war.

However, the White House said the intelligence fell short of what was needed to cross Obama’s “red line” on Syrian chemical weapons.