US media outlet CNN says President-elect Donald Trump may declare a national economic emergency to impose a sweeping program of trade tariffs.

The program could impact both adversaries and allies, CNN reported, citing sources familiar with the matter.

The report on Wednesday says that Trump could use the International Economic Emergency Powers Act to gain the unilateral authority to manage imports.

CNN cites a source as saying Trump has a fondness for the law because it gives broad jurisdiction over how tariffs are implemented.

The report also says that no final decision has been made and that Trump's transition team is exploring other legal options for the program.

Trump repeatedly said during the presidential election campaign that he would introduce more trade tariffs. In August, he said he will impose levies of 10 to 20 percent on all imports.