President Trump on Thursday said he may be open to using trade negotiations to force Mexico to pay for a wall along the Southwest border, a campaign promise he was accused of abandoning earlier this month after he requested $18 billion from Congress to fund the massive project.

“I’ve always said we have to have a wall. I’ve also said Mexico’s got to pay for it. Well, they will pay for it. There are many forms of payment, I could name 10 right now,” Trump told the Wall Street Journal when asked during an interview how he plans to force the United States’ southern neighbor to pay for a border wall.