The White House says President Donald Trump has a "buffet of options" on how to get Mexico to pay for the wall he wants to build along the U.S.-Mexican border. Plans for the controversial wall have soured Mexican relations with the United States, just days into the Trump presidency. Earlier Thursday, White House Press Secretary Sean Spicer told reporters Trump wanted to slap a 20 percent tax on all imports from Mexico. He said the new tax would raise $10 billion a year and "easily pay for the wall." He also said the president discussed the idea with congressional leaders and wanted to include the measure in a comprehensive tax reform package that Congress would have to approve. But later, the White House said the idea is just one of several options on the table for paying for a wall along the southern border. And it said Trump has yet to make a final decision about how the U.S. will recoup the costs of his proposed border wall. U.S. taxpayers initially would foot the bill for the wall, which is expected to cost as much as $15 billion. It is unclear what retaliatory steps Mexico could take if the border tax is approved, because exports to the U.S. are essential to the Mexican economy. Earlier Thursday, Mexican President Enrique Pena Nieto canceled next week's meeting with Trump in Washington after Trump said the talks should be called off if Mexico kept insisting it would not pay for the wall. "The president of Mexico and myself have agreed to cancel our planned meeting scheduled for next week," Trump said. "Unless Mexico treats the United States fairly, with respect, such a meeting would be fruitless, and I want to go a different route. We have no choice." Vital to Mexico It is unclear what retaliatory steps Mexico could take if the tax was approved, because exports to the U.S. are essential to the Mexican economy. Trump made building a wall one of his top promises during the presidential campaign. He often led his supporters in chants of "build the wall, build the wall." The wall along the U.S.-Mexican border would be primarily aimed at stopping illegal immigration into the U.S. But many Mexicans regard the idea of a wall as an insult, and the rough terrain and stretches of private property along the border could make building the wall a long, complicated project. Trump on Thursday also blasted the North American Free Trade Agreement between the U.S., Mexico, and Canada. He called it a "total disaster" for the U.S., costing as much as $60 billion each year in trade deficits with Mexico. "Not to mention millions of jobs and thousands and thousands of factories and plants closing down all over our country," he said. "On top of that are the trillions of dollars the U.S. taxpayers have spent to pay the cost of illegal immigration." Trump and Pena Nieto met in August in Mexico City to discuss immigration, the border wall and other issues. Trump said that he and Pena Nieto did not discuss who would pay for the proposed wall. But the Mexican president said he began their conversation by telling Trump that Mexico would not pay.