John Rood, Under Secretary of Defense for Policy, testified before the House Armed Services Committee on Jan. 29, 2019. (Photo: Screen capture/C-SPAN)

(CNSNews.com) - Senate Majority Leader Mitch McConnell (R-Ky.) told a news conference on Tuesday that "I'm for whatever works, which means avoiding a shutdown and avoiding the president feeling he should declare a national emergency."

On the same day, at a hearing of the House Armed Service Committee, a Defense Department official agreed with two Republican lawmakers that President Trump doesn't need to declare a national emergency to get military assistance in building a border barrier.

The subject arose when Rep. Vicky Hartzler (R-Mo.) pointed to Title 10, Section 284 of the U.S. Code, which authorizes the Defense Department to provide support for counter-drug activities, if such help is requested by appropriate federal or state officials.

The law identifies various activities that DOD is authorized to conduct, including "Construction of roads and fences and installation of lighting to block drug smuggling corridors across international boundaries of the United States."

Hartzler asked Under Secretary of Defense John Rood how long DOD has been providing support to counter-drug operations at the border.

“Congresswoman, we have, at the Department, provided support to the counter-drug missions at the Department of Homeland Security and indeed other civilian agencies for a very long time, for decades. That support continues,” Rood said.

“As you correctly point out, Section 284 of Title 10 does provide the secretary of defense with authority, in performance of that counter-drug mission, such as countering drug smuggling corridors, to erect barrier fencing, provide road construction, things of that nature, to aid in that counter-narcotics mission.”

"So you're saying that Congress has authorized the Department of Defense to build a fence to counter drugs? That is already law," Hartzler said.

"Yes, that's right, if it meets that criteria in Section 284, yes ma'am."

Hartzler said it's clear to her that Congress already has given DOD authority to build border fencing to "make sure that people don't die as a result of transnational drug cartel activity."

Picking up where Hartzler left off, Rep. Mo Brooks (R-Ala.) agreed that Title 10, Section 284 "authorizes President Trump to deploy the military to the southern border to build fences and do a lot of other things."

"It seems to me that 10 U.S. Code 284 can be used by the president of the United States to direct the U.S. military to build a wall," Brooks told Rood.

Rood said as of today, no U.S. military forces have been deployed to the southern border under Section 284.

"You are correct, however, that that use of authority would authorize the secretary of defense to erect barriers, roads, fencing, those type of materials, to disrupt drug smuggling," Rood said.

"Does 10 U.S.C. 284, as you understand it, require the declaration of a national emergency before it is implemented?" Brooks asked.

No," Rood said.

"It does not," Brooks clarified.

"No," Rood repeated.

"Has President Trump, to your knowledge, ever used 10 U.S.C. 284 to direct the military to build the wall that is necessary for border security?" Brooks asked

"No, not to my knowledge, Congressman," Rood replied.

Brooks asked Rood, "If President Trump were to direct the Pentagon, the United States military, pursuant to 10 U.S.C. 284 to build such barriers as are necessary to secure our Southern border from drug trafficking and international crime cartels, would the United States military obey that order?"

"If we judge it to be a lawful order, yes, Sir," Rood replied. "And I assume it would be."