Secretary of State Marco Rubio says President Donald Trump’s desire to acquire Greenland and retake control of the Panama Canal is driven by legitimate national security interests stemming from growing concerns about Chinese activity and influence in the Arctic and in Latin America.

Donald Trump says the U.S. needs control of Greenland and the Panama Canal "for national security." Here's why both places are so important.

President-elect Donald Trump wouldn't rule out military or economic coercion, saying the U.S. needs to stop China. Also a factor: climate change.