LONDON, July 19

Prime Minister David Cameron has declared that Britain needs to take a greater role in destroying the Islamic State group in Syria — his most direct signal to date that he will seek to expand his country’s role in supporting the United States and its allies.

In remarks made to NBC News’ “Meet the Press,” Cameron said Britain must do more to fight the group, also known as ISIL. The remarks posted online Saturday follow a commitment to meet NATO targets on military spending and make plain that Britain now sees the group as an explicit threat to national security.

“We know that we have to defeat ISIL, we have to destroy this caliphate, whether it is in Iraq or in Syria,” he said. “That is a key part of defeating this terrorist scourge that we face.”

The remarks come only days after Britain’s Ministry of Defence acknowledged that British forces have already conducted airstrikes over Syria — albeit only when embedded with coalition forces. Britain has been carrying out surveillance and air-to-air refueling over Syria and launching attacks on neighbouring Iraq and Defence Secretary Michael Fallon has argued that lawmakers should expand the mission to Syria.

Cameron has been reaching out to the opposition Labour Party to win support — trying to build a unified national position and avoid another embarrassing defeat on Syria.