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.

The Tuesday hearing delved into security issues and foreign influence on the foremost maritime channel connecting the Atlantic and Pacific Oceans.

China's influence on the Panama Canal is a major risk to U.S. national security, Sen. Ted Cruz told lawmakers during a Senate hearing on Capitol Hill.

US senators heard sharply different analyses about Chinese influence over the Panama Canal on Wednesday, with some experts suggesting solutions ranging from enhanced trade partnerships to military intervention to regain control of the strategic waterway.

A key focus of Secretary of State Marco Rubio’s visit to Central America this week — his first trip as America’s top diplomat — will be to counter China’s growing influence in the region, the State Department’s top spokesperson said this week,

It’s impossible, I can’t negotiate,” Mulino said when asked about returning the canal to U.S. control. “That is done. The canal belongs to Panama.”

China has fired back at President Donald Trump, dismissing his claim that Beijing has seized control of the Panama Canal as baseless and provocative. Newsweek reached out by email to a Trump representative and to Hutchison Ports, a Hong Kong–based port operator that controls ports near the canal, for comment.

When, fresh from his November election victory, President Donald Trump began musing about buying Greenland, repossessing the Panama Canal, and annexing Canada, many people dismissed his visions of territorial acquisition as a Trumpian pipe dream,

"Our job—where we can'is to provide Latin America with a choice," a U.K. government minister said on Thursday.

This is not about acquiring land for the purpose of acquiring land,” Rubio. “This is in our national interest and it needs to be solved.”