Lawmakers are back on Capitol Hill Saturday after a dramatic showdown led to a federal government shutdown shortly after midnight on the one-year anniversary of President Donald Trump's inauguration.

It is the first time in recent history when government operations shut down while Republicans control both the White House and Congress.

Trump's director of the Office of Management and Budget, Mick Mulvaney, issued a memo to the leaders of federal agencies and executive departments Saturday, telling them to prepare for the possibility of the shutdown continuing into the start of the work week on Monday, saying there is no "clear indication that the Congress will act in time" to fund the government before Sunday night.

Immigration came into sharp focus as one of the topics dividing the two parties in the days, hours and even minutes leading up to the shutdown.

Democrats are accusing Republicans of ignoring the topic of immigration as well as other issues such as public health and veterans in proposed resolutions. Conservatives though portray the stalemate as a case of Democratic obstruction.

At the Capitol on Saturday, Republican leaders including House Majority Leader Kevin McCarthy, R-Calif., focused their ire on top officials across the aisle, particularly Senate Minority Leader Chuck Schumer, D-N.Y.

McCarthy said he believed there was bipartisan agreement to eventually negotiate on four key immigration issues, including protections for persons formally covered under the Deferred Action for Childhood Arrivals (DACA) policy, but said characterized the shutdown as "irresponsible" in the midst of "meeting [and] making progress" on the immigration details.

The White House said Saturday that Trump has been on the phone with Senate Majority Leader Mitch McConnell, R-Ky. and Speaker of the House Paul Ryan, R-Wis. but, "will not negotiate on immigration reform until Democrats stop playing games and reopen the government."

Andrew Kelly/Reuters

The statement echoed early-morning tweets by Trump, in which he attacked Democrats for prioritizing an immigration solution.

"Democrats are far more concerned with Illegal Immigrants than they are with our great Military or Safety at our dangerous Southern Border. They could have easily made a deal but decided to play Shutdown politics instead. #WeNeedMoreRepublicansIn18 in order to power through mess," Trump tweeted.

A subsequent tweet read, "This is the One Year Anniversary of my Presidency and the Democrats wanted to give me a nice present. #DemocratShutdown."

Schumer said he thought negotiators were nearing a deal Friday when he met with Trump. The New York Democrat said he "reluctantly" agreed to fund a border wall in exchange for protections for Deferred Action for Childhood Arrivals (DACA) program recipients.

“The only way out of this is for the president to take yes for an answer," Schumer said from the Senate floor on Saturday, as he accused Republicans of proposing inconsequential remedies that "kicked the can down the road."

McConnell, who pledged early Saturday that there would be a Senate vote on a continuing resolution to keep the government open through Feb. 8, received support on the plan from Sen. Lindsey Graham, R-S.C.

But such a short-term deal still faces opposition from a number of Democratic senators seeking a briefer extension in order to force more focused deliberations on the issues broader than funding.

A top Democratic aide told ABC News that the lack of enthusiasm from the party's senators for the Feb. 8 measure wasn't expected to change Saturday after a House-passed bill with a Feb. 16 deadline failed in the chamber late Friday. The aide pointed to the lack of a comprehensive DACA fix in the bill as a sticking point.

Meanwhile, thousands of activists — many of them galvanized by Trump's election to office a year ago — gathered in cities across the nation for the second annual Women's March, which this year organizers are calling "#PowerToThePolls."

The shutdown also comes exactly one year after Trump said in his inauguration speech: "We will no longer accept politicians who are all talk and no action, constantly complaining but never doing anything about it. The time for empty talk is over. Now arrives the hour of action."

ABC News' Mary Bruce, John Parkinson and Jordyn Phelps contributed to this report.