The move marks the culmination of a decade-long push by the president to tear up climate policies he argues stifle industry.

The activity comes at a time of heightened tensions as talks between Iranian and US officials continue over Iran's nuclear programme.

The International Olympic Committee defends the T-shirt as being part of its Heritage Collection, celebrating styles from all editions of the Games.

The White House calls it the largest deregulation in US history, but environmentalists say it will prove costly for Americans.