PALM BEACH, Fla. — President Trump plans to oust embattled Veterans Affairs Secretary David Shulkin amid an extraordinary rebellion at the agency and damaging government investigations into his alleged spending abuses, three administration officials told the Associated Press on Sunday.

Two officials said an announcement on Shulkin could happen this week, subject to Trump’s final decision as the White House hones in on possible replacements to head the Department of Veterans Affairs. One of the officials rated Shulkin’s chances of being pushed out in the next day or two at ‘‘50-50.’’ The three officials demanded anonymity to discuss a sensitive personnel matter.

The White House did not immediately comment. Shulkin did not respond to a request for comment Sunday.

Navy veteran Richard Roberson stood beside the Lone Sailor statute at the United States Navy Memorial on Saturday morning -- directly in the center of the massive anti-gun violence rally, March for Our Lives.

He watched as thousands of people streamed by, many of them kids -- all of them urging Congress for stricter gun-control measures. The 71-year-old broke down as he explained why he felt compelled to make the trip into Washington from his home four hours away in rural Virginia.

"If you're 20 years old, and you're on a Navy hospital ship in Vietnam, it stays with you forever when you see what assault rifles do," Roberson said. "Quite frankly, my generation has made a mess of the country. These kids are the future."

A few dozen veterans gathered at the memorial to stand together in support of March for Our Lives and the students who helped to lead it. Many more veterans were likely dispersed through the large crowd, said Air Force veteran Pam Campos, who organized the veteran contingent at the Washington march.

By noon, a mass of people stretched from the U.S. Capitol down Pennsylvania Avenue toward the White House. Organizers were hoping to match attendance at last year's women's march, which was one of the biggest protests in the capitol and far surpassed predictions of 300,000 demonstrators.

The official mission statement for March For Our Lives claims the purpose of the rally --and hundreds of sister marches worldwide -- is to demand that Congress act on a "comprehensive and effective bill" to address gun reform in the wake of the 17 people killed at Marjory Stoneman Douglas High School in Parkland, Fla., on Feb. 14.

It was the first protest Marine Corps veteran Steven Kiernan, 30, had ever attended.

"I was always cynical about these kinds of things. You come home from Iraq and everyone seems so disengaged and not interested," Kiernan said. "Seeing this, it's given me hope for the future for the first time in a while. These kids aren't willing to accept the world as it is -- they want to change it."

STUTTGART, Germany -- The U.S. military has launched its first airstrike against al-Qaida in Libya as operations expand beyond targeting the Islamic State group.

"The United States will not relent in its mission to degrade, disrupt, and destroy terrorist organizations and bring stability to the region," U.S. Africa Command said in a statement on Monday.

The strikes on Saturday were launched near the remote Saharan desert town of Ubari, long a crossroads for bandits, various tribal groups, traffickers and militants.

Until now, AfriCom has focused its military efforts in the north around the coastal city of Sirte. In 2016, about 500 airstrikes were carried out during a four-month campaign to dislodge ISIS from the town. The airstrikes were coordinated with forces on the ground aligned with the Libyan government.

Some fighters managed to flee and AfriCom has continued to carry out occasional strikes in other parts of the country.

But the attack in Ubari is the first known strike that reached deep into Libya's isolated southwestern region, a place where al-Qaida in the Islamic Maghreb has long maneuvered between borders with Niger and Algeria.

"These terrorists have used safe havens and freedom of movement in Libya to launch external terror attacks into neighboring countries," AfriCom said.

The command did not say if there were signs that al-Qaida affiliates are gaining in strength in the region, a development that could potentially prompt an escalation of U.S. operations.

The Saturday strike comes as AfriCom adds capabilities to carry out surveillance operations and possibility strikes in the broader Sahel region. In the central Niger city of Agadez, the U.S. military is developing a new drone site that will extend its reach into southern Libya.

The base is expected to be operational later this year. The Nigerien government authorized the armed drone flights in the wake of an October ambush that killed four U.S. soldiers.