The President told supporters at a "Make America Great Again" rally in Phoenix, Arizona, on Tuesday that the opposition Democrats were being "obstructionist", The Hill magazine reported.
Funding for Trump's proposed border wall, a promise that was at the centre of his 2016 presidential bid, is poised to be at the centre of debate when Congress negotiates a new government funding bill. If a new bill is not passed, the government will shut down on October 1.
But Republicans will need the support of Democrats to secure funding for the wall in a government spending bill, which they are unlikely to get, reports said.
Democrats are staunchly opposed to funding for the wall, setting up a challenge and tense negotiations over the government's funding.
In his speech, Trump said the Democrats were "putting all of America's safety at risk" by opposing the wall. He said immigration officers who worked in the area said it was "vital" to stem the flow of illegal immigrants.
The Department of Homeland Security accepted designs for the wall earlier this year. Vendors were instructed that the wall should be at least 18 feet high, have features to prevent climbing over and tunnelling beneath the structure, and to make the designs "aesthetically pleasing" on the US side, the report said.