WASHINGTON — President Obama will move as soon as next month to defang the 54-year-old American trade embargo against Cuba, administration officials said Thursday, using broad executive power to defy critics in Congress and lift restrictions on travel, commerce and financial activities.

The moves are only the beginning of what White House officials and foreign policy experts describe as a sweeping set of changes that Mr. Obama can make on his own to re-establish commercial and diplomatic ties with Cuba even in the face of angry congressional opposition.

“The embargo is a container — it’s been that way since President Eisenhower — that’s had regulations and laws put into it and taken out of it and mixed about,” said John Kavulich of the U.S.-Cuba Trade and Economic Council. “President Obama is saying, ‘I’m going to leave a shell, but it’s going to be a proverbial Easter egg — it’s going to be hollow.’ ”