President Donald Trump responded to House Speaker Nancy Pelosi on Thursday, vowing that he would not cave in the shutdown fight over border security.

During a press conference, Pelosi claimed she did not understand why Trump was insistent on getting funding for his border barriers. Trump responded instantly.

“Very simply, without a Wall it all doesn’t work,” Trump wrote on Twitter. “Our Country has a chance to greatly reduce Crime, Human Trafficking, Gangs and Drugs. Should have been done for decades.”

The partial government shutdown continues into its 34th day.

The president said he would continue to demand border barrier funding as part of a bill to fund the government.

The Senate on Thursday will vote on two government funding proposals on the Senate floor, one Republican proposal that offers $5.6 billion in funding for physical barriers on the border and a proposal from Democrats that will fund the government without border barrier funding.

Trump vowed not to concede to Democrats on the shutdown without a deal to secure the border.

“We will not Cave!” he wrote.

Without a Wall there cannot be safety and security at the Border or for the U.S.A. BUILD THE WALL AND CRIME WILL FALL! — Donald J. Trump (@realDonaldTrump) January 24, 2019