President Donald Trump reasserted his position Thursday that any bill funding the government must include more money for border security.

“I’ve made my position very clear,” he said. “Any measure that funds the government must include border security.”

Trump commented at length on the negotiation process at the White House during a signing ceremony for the farm bill.

The president said he was comfortable describing border security as “steel slats,” not necessarily a wall, admitting that he was giving Democrats “a little bit of an out.”

“We don’t use the word wall necessarily, but it has to be something special to get the job done,” Trump said.

But he spoke favorably about walls, even if they were made of steel slats, noting that it would only cost a “tiny fraction” of the budget.

“Walls work whether we like it or not, they work better than anything,” Trump said. “We have proposed a steel slat barrier to halt the deadly flow of these illegal traffickers, smugglers, and terrorists.”

Earlier in the day, he met House Republican leaders about possibly adding more border security funds to the continuing resolution bill passed by the Senate.

The president said that all leaders in Washington D.C. had sworn to protect the United States. Despite many members of Congress already leaving Washington D.C. for the Christmas holiday, Trump demanded that everyone come together to fund the government and keep it open.

“In life, there are certain principles worth fighting for, principles that are more important than politics, party, or personal convenience,” Trump said. “The safety and security and sovereignty of the United States is the most important principle of all.”