With less than a day to go before a promised fresh round of President Donald Trump’s tariffs on April 2, which he has dubbed “liberation day,” the president still hasn’t revealed how sweeping those tariffs will be.

However, sources have revealed to ABC News some of the options the administration has been debating in recent weeks. They include a 20% flat tariff rate on all imports, which officials say could raise more than $6 trillion of revenue for the U.S. government.

Also said to be under consideration is different tariff levels for each country to match the barriers they impose on U.S. products. Countries that strike deals with the U.S. won’t be hit with tariffs, sources told ABC News.

White House press secretary Karoline Leavitt said countries have called Trump about the upcoming tariffs but did not provide details about which countries or how many he has had conversations with.

“I don’t have a specific number, but I can tell you, there have been quite a few countries that have called the president and have called his team in discussion about these tariffs,” Leavitt said

Administration officials have also publicly spoken about imposing tariffs on about 15% of countries with the largest trade imbalances with the U.S.

The final details still aren’t set in stone, the sources stressed. Leavitt said Tuesday that the president is currently working with his team “perfecting it to make sure this is a perfect deal for the American people and the American worker.”

Trump has at times downplayed the scope of the tariffs. Last week, he said his reciprocal tariffs would be “very lenient … in many cases, less than the tariff that they’ve been charging us for decades,” and that people would be “very pleasantly surprised.”

Whatever the tariffs might be, the Trump administration believes they will have an overall positive effect on the U.S. economy, including preventing other countries from “ripping off” the U.S. The administration has also insisted that tariffs will boost domestic industries and jobs, by convincing companies to manufacture in the U.S. rather than importing goods from overseas.

Tariffs can be used as a negotiating tool for other countries to crack down on illegal immigration and the flow of drugs into the U.S., according to Trump, a rationale he has cited in his decision to levy tariffs against Canada, Mexico and China.

The president has also touted tariffs as a way to generate revenue and help balance the budget.

Many experts note, however, that some of these goals are contradictory and cannot be achieved simultaneously. They further warn that the tariffs run the risk of tipping the U.S. into a recession.

Canadian Prime Minister Mark Carney also told reporters on Tuesday that they would “put in place retaliatory measures” if Trump imposed “additional measures” against Canada.

The reciprocal tariffs Trump is set to announce Wednesday are in addition to 25% tariffs on imported vehicles set to go into effect on Thursday. Last month, Trump announced 25% tariffs on imports of aluminum and steel.

ABC News’ Max Zahn contributed to this report.