With a deadline looming for Democrats and Republicans to reach an agreement regarding President Donald Trump’s demand for more than $5 billion to construct a wall along the U.S.-Mexico border, Sen. Richard Shelby, R-AL, said he believes the chances are “slim” that legislators will come to an agreement.

After the recent government shutdown, the longest in history at 35 days, lawmakers reached a temporary agreement that allowed for the government to reopen for three weeks while negotiations continued.

Shelby’s remarks came during an interview on CNN’s “State of the Union” Sunday.

“We’ve got to have a comprehensive approach to this,” Shelby said. “I believe that we’ve got a chance to move things. Will we? I don’t know. The president could be right, we could be wasting our time. On the other hand, we could come up with a solution. But as long as the speaker and the president are way at odds, the chances of us reaching an agreement are slim. But it could happen.”

Shelby serves as chairman of the Senate Appropriations Committee and took part in a conference tackling Homeland Security appropriations last week.

During the meeting, Shelby called for Democratic lawmakers to take serious their pledges to negotiate on border security in exchange for reopening the government.

“These negotiations must not end in platitude or future promises,” Shelby said. “They must yield results that actually secure the border.”

Shelby claims that “border patrol officials” have told him that efforts to secure must include “technology, infrastructure, personnel and physical barriers.”

“Our border patrol tells us that they need physical barriers to help them do their job,” Shelby said. “Not from coast to coast, but strategically placed where traffic is highest. Combined with technology, manpower and other infrastructure, these strategic barriers comprise a comprehensive solution that is capable of fully securing the border.”