American flags fly near the Washington Monument on Saturday. The U.S. government officially entered a partial shutdown early Saturday as Senate Democrats and a handful of Republicans blocked a bill to fund the government. The two parties failed to break a deadlock over immigration. (Andrew Harrer/Bloomberg)

The U.S. military faced a variety of consequences as a result of a federal government shutdown Saturday, with U.S. troops working at least temporarily without pay, thousands of civilian employees furloughed and Republicans and Democrats alike saying that their opponents should do better for the troops.

Defense Secretary Jim Mattis said in a memo released by the Pentagon on Saturday that the U.S. military will continue to carry out operations across the world, but the shutdown already was prompting the cancellation or delay of training for reserve units and having other effects. Mattis pledged to do his best to mitigate disruptions and financial impact on military families.

“We will continue to execute daily operations around the world — ships and submarines will remain at sea, our aircraft will continue to fly and our warfighters will continue to pursue terrorists throughout the Middle East, Africa, and South Asia,” Mattis wrote. “While training for reservists must be curtailed, active forces will stay at their posts adapting their training to achieve the least negative impact on our readiness to fight.”

Mattis added: “Steady as she goes — hold the line. I know our Nation can count on you.”

According to a Pentagon planning memo posted this week, all active duty uniformed personnel are to continue their duties, but they will not be paid until after the shutdown is resolved.

Col. John Thomas, a spokesman for U.S. Central Command, said the shutdown would not have a significant impact across the Middle East, where U.S. troops are conducting operations against militants in Syria, Afghanistan, Yemen and elsewhere, and where the U.S. military has a host of major bases.

President Trump accused the Democrats on Saturday morning in a tweet of “holding our Military hostage over their desire to have unchecked illegal immigration,” a reference to the dispute that is at the heart of the shutdown.

But the situation wasn’t that simple. While Trump, House Speaker Paul D. Ryan (R-Wis.), Senate Majority Leader Mitch McConnell (R-Ky.) and other Republicans blamed the Democrats, Sen. Claire McCaskill (D-Mo.) made an effort shortly after midnight to get the troops’ salaries and death benefits paid through the shutdown.

“I want to make sure that tonight we send a very clear signal that we don’t want one moment to pass with there being any uncertainty of any soldier anywhere in the world that they will be paid for the valiant work they do for our national security,” McCaskill said, calling for a resolution to pay the troops.

McConnell scuttled the effort, objecting to her motion.

The pay situation threatened the financial well-being of service members, whose annual salaries begin at less than $30,000. As McCaskill noted, Congress has historically given the military back pay when a shutdown occurs or passed a bill that pays them during a work stoppage. U.S. troops are paid twice a month, and the next check is expected Feb. 1.

As Mattis predicted in public remarks Friday, military reservists across the country traveled in preparation for scheduled training this weekend, only to be sent home after the shutdown at midnight. While some live close to their units, it’s common for reservists to travel several hours to bases for drilling.

Bryan Salas, a Marine Corps veteran, said his son traveled from West Virginia on Friday to report to training this weekend at Marine Corps Base Quantico, Va., but returned hours later.

“He just went back to West Virginia about a half-hour ago,” Salas said around noon Saturday. “It’s just time wasted. He’s a student, but there are others who have jobs and their own businesses who planned for this training.”

A soldier assigned to the Army’s 450th Civil Affairs Battalion in Maryland said that his unit is preparing for a month-long exercise in March, and was planning to work on weapons qualifications this weekend in advance. The battalion includes numerous congressional staff members, he said.

“We have dozens of mission-planning tasks to complete since we just got our initial operations order for the exercise on Thursday,” said the soldier, speaking on condition of anonymity in order to be candid. “Not to mention all the equipment that needs to be prepared to move by rail. This puts us really far behind with only two days scheduled in February to prepare for a month-long training.”

While uniformed personnel are largely shielded from the shutdown’s effects, civilian employees whose jobs are not deemed critical to defense operations will be furloughed, according to the same Pentagon memo.

There are more than 740,000 Defense Department civilians. Mattis said Friday that about half of them would be furloughed. The Defense Department did not respond to repeated requests on Saturday to provide a precise number of furloughed employees.

Susanna Blume, who was a Pentagon official at the time of the last shutdown in 2013, said Pentagon leaders may not actually know that number, because decisions about which civilian employees will stay home are often delegated down the bureaucracy, and the roster of furloughed personnel can change day to day given work requirements.

Former officials said that the impact of the shutdown, especially if it goes on for an extended of period of time, may be felt most keenly in military readiness because of its effect on civilian or reserve personnel involved in maintenance and training.

“Disrupting those schedules often has a domino effect,” Blume said. Military intelligence activities, which often rely on civilian personnel, could also be affected, she said.

Mark Cancian, who was a senior budget official in 2013, suggested that if lawmakers resolve the impasse in a matter of days, the episode would be “disruptive but not catastrophic.” Even so, he said, the act of planning for a shutdown would cost taxpayers millions of dollars.

Already on Saturday, other effects were felt across the military. One particularly sensitive one is the temporary suspension of $100,000 payments promised to military families in the event their loved one dies so that they can travel and prepare funerals. Several nonprofits, including Fisher House and the Tragedy Assistance Program for Survivors (TAPS), offered to assist families that might be in need.

Defense Department outreach efforts were curtailed, including aerial flyovers at sporting events, band performances and related travel, according to a memo by Dana W. White, Mattis’s assistant for public affairs.

The American Forces Network, which carries television broadcasts of sporting events and other programming, was taken off air at midnight, leaving deployed U.S. troops without one common way to watch National Football League playoff games this weekend.

But early Sunday, the Defense Department said that TV and radio broadcasts were deemed essential, and that two AFN channels — news and sports — would remain on.

According to White, uniform leadership at AFN, the comptroller and legal team were able to turn on one channel based on operational necessity and funds had already been paid on the contract. The sports channel was chosen because it doesn’t cost any more money or manpower to manage a second channel, in compliance with shutdown guidance.

“We will continue to find solutions to support our troops at home and abroad. Congress must come to a resolution, support our troops and pass a budget soon,” White said in a statement.

While duties performed by uniformed personnel overseas are not immediately affected, the signal sent to troops in areas such as U.S. Africa Command (AFRICOM), where forces are deployed under hazardous conditions in Somalia, Niger and elsewhere, did not appear to be a welcome one.

“We hope Congress has our country’s best interest in mind,” said Col. Mark Cheadle, an AFRICOM spokesman, when asked about the shutdown.

Missy Ryan contributed to this report, which was updated with additional reporting.