(CNSNews.com) - As the United States focuses on national security threats emanating from China and Russia, it hasn't lost sight of the threat posed by Iran and North Korea.

At a congressional hearing on Thursday, Joint Chiefs Chairman Gen. Mark Milley said Iran threatens to destabilize the Middle East with its continuing support for terrorists and proxy forces.

"Also, Iran is taking actions to improve its capabilities to produce a nuclear weapon, should it make the decision to do so, while continuing to build its missile forces," Milley told the the House Appropriations Committee on Defense.

"From the time of an Iranian decision...Iran could produce fissile material for a nuclear weapon in less than two weeks, and would only take several more months to produce an actual nuclear weapon.

"But the United States remains committed as a matter of policy that Iran will not have a fielded nuclear weapon.

"And we, the United States military, have developed multiple options for our national leadership to consider if or when Iran ever decides to develop an actual nuclear weapon."

Milley said North Korea's continued ballistic missile testing and nuclear weapons development also "pose real threats to our homeland as well as our allies and partners in the Indo-Pacific."

Just hours after Milley and Defense Secretary Lloyd Austin testified, the Defense Department announced it had retaliated for an Iranian drone attack on a U.S. base in northeastern Syria:

"Earlier today, a U.S. contractor was killed and five U.S. service members and one additional U.S. contractor were wounded after a one-way unmanned aerial vehicle struck a maintenance facility on a Coalition base near Hasakah in northeast Syria," Austin said in a statement on Thursday night:

"The intelligence community assess the UAV to be of Iranian origin," the statement continued:

"At the direction of President Biden, I authorized U.S. Central Command forces to conduct precision airstrikes tonight in eastern Syria against facilities used by groups affiliated with Iran’s Islamic Revolutionary Guards Corps (IRGC)

"The airstrikes were conducted in response to today’s attack as well as a series of recent attacks against Coalition forces in Syria by groups affiliated with the IRGC.

"These precision strikes are intended to protect and defend U.S. personnel. The United States took proportionate and deliberate action intended to limit the risk of escalation and minimize casualties."

Austin said two of the wounded service members were treated at the base, while three others, along with the injured U.S. contractor, were sent to coalition medical facilities in Iraq.