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 in the Arctic and in Latin America.

Former U.S. senator from Florida Marco Rubio jumps into new role as secretary of state with flurry of phone calls, planned trip to Panama.

President Donald Trump's new Secretary of State Marco Rubio announced that a U.S. citizen imprisoned in Belarus under Joe Biden has since been released.

The new secretary of state took center stage in a diplomatic rift with Colombia over deportation flights, adding teeth to Trump's threats of sanctions.

The U.S. may place a "very big bounty" on the top leaders of the Taliban, Secretary of State Marco Rubio said on Saturday, adding he was hearing that the Taliban held more American hostages than previously reported.

Secretary of State Marco Rubio ordered an immediate stop to the flow of almost all U.S. foreign assistance, pending a review, according to an internal State Department cable obtained by NBC News. A waiver was issued for foreign military financing for both Israel and Egypt,

The directive follows President Donald Trump’s executive order Monday pausing new obligations and disbursements of foreign aid pending review.

Panama will be one of the first stops for new Secretary of State Marco Rubio as he heads overseas late next week

State Department staff were instructed to “suspend any application requesting an X sex marker” and to “suspend any application where the applicant is seeking to change their sex marker.”

Secretary of State Marco Rubio said on Thursday that President Donald Trump's offer to “buy” Greenland is “not a joke”, adding that acquiring the semi-autonomous Danish territory was in the US “national interest”.