Congress has been unable to pass funding packages for seven federal agencies, mainly due to Trump’s stubborn demands for $5 billion to build his border wall. With funding deals expiring at midnight tonight, hundreds of thousands of federal employees will be either out of work or expected to work without pay until the government resumes full function in 2019.

Among those affected are more than 420,000 employees required to keep working through the shutdown, including those in the Department of Homeland Security, the FBI, the DEA, and Forest Service firefighters. With dozens of federal agencies expected to close down, national parks, museums, and zoos may be shuttered, with housing agencies warning that loan processing and approvals may be significantly delayed.

Aside from disrupting government services, shutdowns worsen deficits with financial losses in productivity. The longest government shutdown took place under the Clinton Administration, lasting 21 days and costing approximately $1.4 billion. The 2013 shutdown under Barack Obama lasted 16 days and cost about $2 billion.

Trump took to Twitter to blame Democrats for their refusal to offer more than $1.3 billion to fund the border wall. He posted, “If the Dems vote no, there will be a shutdown that will last for a very long time.” After Congress voted and Trump still did not receive his inflated amount of $5 billion, he followed up with, “The Democrats now own the shutdown!”

As of early Friday evening, Congress had made no progress in settling the border wall dispute. Government agencies had been alerted on Thursday to prepare to freeze their functioning for an indeterminate amount of time.

“I hope we don’t [shut down],” Trump told the press on Friday afternoon at a bill signing event at the White House. “But we are totally prepared for a very long shutdown and this our only chance that we’ll ever have in our opinion, because of the world and the way it breaks out, to get great border security.”