"Secretary Shanahan will no longer travel to Europe as he has determined remaining present in DC would allow him to more effectively coordinate with NSA and the State Department in Venezuela and to continue coordination with DHS for support along the Southwest border," his spokesman Joe Buccino said.

Shanahan had planned to embark on a tour of Germany, Belgium and Britain, starting Thursday.

US Secretary of State Mike Pompeo said earlier Wednesday President Donald Trump was prepared to take military action to quell the crisis in Venezuela.

Shanahan was due to attend ceremonies in Germany and Belgium marking the change of commanders for US European Command and NATO's Supreme Allied Commander Europe.

He was also expected to meet his British counterpart Gavin Williamson before his return on Saturday.

Venezuelan was bracing Wednesday for anti-government protests called by opposition leader Juan Guaido in a bid to pile pressure on President Nicolas Maduro.

Pro-Maduro rallies were also expected, a day after violent clashes erupted in the capital Caracas following Guido's call on the military to rise up against Maduro, who claimed the insurrection had failed.

The United States is among some 50 countries that recognize Guaido, the opposition leader who declared himself interim president in January in a bid to replace Maduro, whom he has branded as illegitimate.