Visiting a border patrol station in McAllen, Trump viewed tables piled with weapons and narcotics.
Republicans and Democrats have made virtually no progress toward reaching any kind of a deal that would end the standoff over the President's border wall that triggered the shutdown.
President Trump seems determined to find a way to fund a border wall between the USA and Mexico - even if it means diverting billions of dollars of aid originally earmarked for Puerto Rico and other communities recovering from disasters. In the meantime, hundreds of thousands of federal workers are set to miss paychecks Friday.
The ongoing partial government shutdown hit a new milestone on Friday by matching the record for the longest government shutdown in United States history.
Pelosi has not said how House Democrats would respond to Trump declaring a national emergency, but she predicted a bipartisan rejection of an attempt by the White House to skirt Congress's power.
As for declaring a national emergency to jump-start wall construction, Trump said he was seriously considering such a move, which would likely face legal challenges.
It is the latest sign that the administration is laying the groundwork for a possible emergency order as negotiations between Trump and congressional Democrats to reopen the partially shuttered government have ground to a halt.
"If and when the president does that you'll find out how we will react", Pelosi said.
A congressional official said the White House has directed the Army Corps of Engineers to look for billions of dollars earmarked a year ago for disaster response for Puerto Rico and other areas that could be diverted to a border wall as part of the emergency declaration. Like almost all drugs trafficked across the border, they were intercepted by agents at official ports of entry, he was told, and not in the remote areas where he wants to extend tall barriers. Across the street, a smaller group chanted back: "Build that wall!"
House Speaker Nancy Pelosi and Senate Democratic leader Chuck Schumer forcefully rebutted the President in a speech of their own Tuesday where Pelosi accused Trump of "holding the American people hostage" to his demands.
That's the same length of time as the 21-day shutdown that stretched from December 1995 to January 1996 as a result of a clash between President Bill Clinton and the GOP Congress.