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.

Rubio defended Trump's proposed territorial expansions as a 'national interest,' while Denmark and Greenland firmly rejected offers amid concerns over potential military action.

A simmering diplomatic stand-off over deportation flights spilled onto social media Sunday, threatening the once close relationship between the US and Colombia and further exposing the anxiety many feel in Latin America towards a second Trump presidency.

Less than a week into his presidency, Donald Trump has briefly engaged in his first international tariff dispute. And the target wasn't China, Mexico or Canada - frequent subjects of his ire - it was Colombia, one of America's closest allies in South America.