The mandate could leave the US without Senate-confirmed representatives for months in key countries like Germany and Britain, the Times notes.
Incoming presidents often grant ambassadors grace period to complete their diplomatic business while their successors are in the confirmation process.
The decision has also left diplomats scrambling to secure new visas, living arrangements and schools for their children, including Ambassador to Costa Rica Stafford Fitzgerald Haney, who diplomats say has four school-age children and a wife battling breast cancer. The State Department has reportedly informed all ambassadors to submit their resignations effective 20 January and asked those who want an extension to formally submit their requests. It applies to everyone and no exceptions will be made.
Top Trump aide suggests Russian Federation sanctions were 'disproportionate'
Republicans in Congress have said they intend to hold hearings into election hacking by the Russian intelligence services. On Sunday his communications director, Sean Spicer , said the president-elect had no intention of stopping tweeting .
According to diplomats familiar with the text of the decree, the document does not allow for exceptions.
A senior Trump transition official said there was no ill will in the move, describing it as a simple matter of ensuring that Mr. Obama's overseas appointees leave the government on schedule, just as thousands of political aides at the White House and in federal agencies must do.
The move will also impact the United States envoy to India, Rich Verma, the first Indian American to be named envoy to India, who was picked by Barack Obama for the job in 2014 and arrived in India days before the United States president's visit the following year.
On Jan. 20, inauguration day, the people of South Florida will join with people across the country to denounce Donald Trump's xenophobic agenda.