Secretary of State Marco Rubio said on Thursday he had "zero doubt" that China has a contingency plan to shut down the Panama Canal in the event of a conflict with the U.S. and that Washington intends to address what it sees as a national security threat.

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.

Secretary of State Marco Rubio declared Thursday that President Trump’s interest in taking control of Greenland and the Panama Canal “is not a joke” and vital to US national security interests. “This is not a joke,