President-Elect Donald Trump is contemplating calling a national economic emergency to implement his wide-reaching tariff policies, four sources familiar with the matter told CNN.

A declaration of this nature will give Trump power to create the tariff program he made a pinnacle of his campaign for the White House through the International Economic Emergency Powers Act, CNN reported. Also known as IEEPA, the act allows the president to oversee imports in a period of national crisis.

Stock futures weakened following the CNN report and the U.S. dollar gained in value against most other currencies.

CNN’s sources noted that a final decision has not been reached on whether Trump will declare a national emergency. Trump’s team is also evaluating alternative legal arguments, such as pointing to specific sections of the U.S. trade law, per CNN’s reporting.

Trump pitched taxes on imports frequently on the campaign trail, calling at times for fees of 60% or more on Chinese products. Weeks after his victory, the Republican vowed to hike tariffs on Chinese imports by 10% and slap 25% fees on products coming from Canada or Mexico.

The Washington Post reported Monday that Trump would narrow the focus of his tariffs, an approach Wall Street seems to favor. But the President-Elect later denied that report.

Read CNN’s full story here.