Rubio said he could not predict if Trump would succeed in buying Greenland from Denmark or restoring American authority over the Panama Canal while he is in office.

By Simon Lewis and Matt Spetalnick WASHINGTON (Reuters) -When Marco Rubio arrives in Latin America this weekend on his first foreign trip as Donald Trump's secretary of state, he'll find a region reeling from the new administration's shock-and-awe approach to diplomacy.

President Donald Trump's suggestion of the U.S. taking control of the Panama Canal has a legal basis partly due to potential treaty violations involving Chinese activities in Panama.

WASHINGTON (Reuters) - 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.

Panama has owned and administered the Panama Canal for nearly three decades. President Trump wants to change that to counter growing Chinese influence in Latin America.

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.

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

The Panama Canal’s future security may depend less on scrutinizing foreign presences and more on rekindling the kind of robust American partnership that made the Canal’s success possible in the first place.

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.”

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,