MILWAUKEE- The British Ambassador to the United States, Sir Peter Westmacott, spoke exclusively with CBS 58 about the growing danger of ISIS.

Westmacott was in Milwaukee to speak with local business leaders as part of his first trip to Wisconsin.

The ambassador called the threat posed by ISIS a shared problem that affects national security in countries around the world.

He added that there is a need to counter that threat.

Westmacott spoke about President Obama, along with British Prime Minister David Cameron and other heads of state from around the world, formulating a plan to deal with ISIS at the NATO summit in Wales.

He said they worked on a coalition in support of the new Iraqi government that would push back and ultimately defeat the terrorist group.

According to Westmacott, there is significant homegrown terrorist activity in the United Kingdom in comparison with the U.S.

He said his county's ministers suspect about 500 British subjects have left the country to join terrorist organizations in the Middle East.

Many of those people have come back into the country as well.

During his time in Milwaukee, Westmacott said he met with Mayor Tom Barrett.