President Trump stood firm Friday on his demands for a border wall after the second White House meeting with congressional leaders this week broke up with no apparent deal, warning Democrats the partial government shutdown could last "years" and saying he could even declare a "national emergency" to bypass Congress if necessary.

"We can call a national emergency [to build a border wall] because of the security of our country," Trump told reporters in the Rose Garden, during a lengthy and impromptu press conference.

"I may do it," he said, before adding, "If we can do it through a negotiated process, we're giving it a shot."

Host of Fox News Sunday Chris Wallace joined Fox News Radio's Guy Benson and Marie Harf to discuss the government shutdown and this week's Fox News Sunday.