Updated

The top U.S. general for homeland defense says there is no military threat coming from the southern border with Mexico, but his focus in on "very real" threats from China and Russia.

Air Force Gen. Terrence O'Shaughnessy, commander, U.S. Northern Command and North American Aerospace Defense Command, told a Senate committee Tuesday that America has vulnerabilities in the Arctic region.

He says proposed barriers along the U.S.-Mexico border could increase security. President Donald Trump has declared a national emergency along the southern border to fund his proposed wall.

Senators are questioning the need for the wall and suggesting U.S. troops are being used as political props in a fake emergency.