Turkey says its ground forces are advancing into northern Syria. This comes just hours after Turkish forces pounded Kurdish targets from the air.

Turkey's Defense Ministry says since this invasion began, Turkish jets and artillery have hit nearly 200 targets just east of the Euphrates River.

Turkey began its offensive in northern Syria on Wednesday with airstrikes against Kurdish fighters before ground troops began crossing the border later in the day.

Expectations of an invasion increased after President Trump withdrew U.S. troops from the area. However, the President had a message for Turkey's leader when asked what happens if the Kurds are wiped out.

''I'll wipe out the economy if that happens. I'm sure that he, I hope that he will act rationally'' said President Trump. 

The Kurds have been America's only allies in Syria fighting ISIS. But a senior U.S. official tells CBS News that Kurdish operations against ISIS are now "effectively paused."