President Donald Trump on Tuesday signed an executive order launching an investigation into the "national security risks posed by U.S. reliance on imported processed critical minerals and their derivative products," according to a fact sheet on the order.

The president has used Section 232 investigations as a precursor to implementing tariffs, as he did with aluminum and steel. On Monday, the White House acknowledged it had ongoing Section 232 investigations into pharmaceuticals and semiconductors.

The White House notes that critical minerals play an important role in our defense industrial base, and are required for everything from radar systems to jet engines, to secure communications.

However, the U.S. relies on foreign sources for many of these materials.

“Foreign producers have engaged in price manipulation, overcapacity, and arbitrary export restrictions, using their supply chain dominance as a tool for geopolitical and economic leverage over the United States,” The White House said in the fact sheet on the order.

The order calls on the secretary of commerce to submit a final report and recommendations to the president within 180 days of the investigation getting underway.

-ABC News' Michell Stoddart, Molly Nagle and Hannah Demissie

President Donald Trump signed an executive order on Tuesday rescinding two executive actions issued by former Presidents Jimmy Carter and Bill Clinton that constrain federal office locations.

According to a fact sheet provided by the White House, Trump’s executive order allows "federal agencies to select office space and facilities based on cost-effectiveness, mission suitability, and the needs of the American people."

The administrator of the General Services Administration will be tasked with updating federal office space management regulations to conform with the order.

The White House argues in its fact sheet that by eliminating the executive actions from Carter and Clinton the Trump administration is making it easier to bring federal services to Americans.

-ABC News' Michell Stoddart, Molly Nagle and Hannah Demissie

Trump signed an executive order Tuesday aimed at lowering healthcare and prescription drug costs.

The order included a directive to improve the program for Medicare to negotiate drug prices, plans to create a program to get better prices for the most expensive drugs, including insulin and directed the FDA to approve state importation programs and approvals for generic drugs.

According to a fact sheet about the order, the government is looking to "eclipse the 22% in savings achieved" by the first year of Medicaid's program to negotiate drug prices. The order also says that the government plans to align the payment with what hospitals pay for them, which the White House says is sometimes "35% lower than what the government" pays.

The order also aims to standardize Medicare costs of drugs regardless of care facility, which the White House says can lower prices by as much as 60%.

-ABC News' Michelle Stoddart

Dan Caldwell, a senior adviser to Defense Secretary Pete Hegseth, has been placed on administrative leave as part of a leak investigation, a U.S. official told ABC News on Tuesday.

Caldwell is a longtime adviser to Hegseth, long before he was named to be the secretary of defense, and was placed on leave following an "unauthorized disclosure," Reuters reported.

On March 21, Joe Kasper, the Defense Department’s chief of staff, directed the "Director for Defense Intelligence (Counterintelligence, Law Enforcement, and Security) to support OSD in leading an investigation into unauthorized disclosures of sensitive and classified information across the Department of Defense."

That memo authorized the use of polygraphs that will be inline with "applicable law and policy" for an investigation that he said would begin immediately.

It is unclear if Caldwell underwent a polygraph.

-ABC News' Luis Martinez