Pentagon officials announced sweeping travel restrictions for troops and their families late Friday night that will halt all domestic travel, including duty station moves and temporary assignments, for nearly two months as officials try to stem the spread of the deadly coronavirus.

Starting Monday, service members, their families and Defense Department civilian workers will be restricted in how they can move about the U.S. and its territories. The unprecedented moves were approved by Deputy Defense Secretary David Norquist and extend through May 11.

A memo outlining the restrictions say the continuing spread of the new coronavirus, or COVID-19, necessitates immediate action.

"These restrictions are necessary to preserve force readiness, limit the continuing spread of the virus, and preserve the health and welfare of Service members, DoD civilian employees, their families, and the local communities in which we live," the memo adds.

Related: Here’s What the Coronavirus Travel Ban Means for Military Families

The measures were announced just hours after President Donald Trump declared the global pandemic a national emergency in the U.S.

The new rules apply to all Defense Department military and civilian personnel assigned to military bases or facilities inside the U.S. and its territories. The memo also applies to family members of those personnel.

It temporarily halts permanent change of station moves and temporary duty assignments, but allows travel for medical reasons.

Those already out on temporary assignments will be allowed to return to their home station when that mission ends. Service members approaching retirement or end-of-duty contracts are also exempt from the travel restrictions.

Otherwise travel will only be approved if it's determined to be mission-essential, is necessary for humanitarian reasons, or warranted due to extreme hardship, the memo adds. Only top brass or civilian leaders are allowed to grant those exemptions.

"These exceptions are to be done on a case by case basis, shall be limited in number, and shall be coordinated between the gaining and losing organizations, as appropriate," the memo states.

Another memo also issued Friday night introduced a host of new restrictions at the Pentagon. Outside tours of the building are canceled, international military partners will no longer be allowed to visit, and anyone who has traveled outside the U.S. must not enter the Pentagon for at least 14 days.

A news release from the Defense Department announcing the new rules says additional guidance surrounding the coronavirus will be issued "as conditions warrant."

"Our goal is to remain ahead of the virus spread to our military force remains effective and ready," it states.

-- Gina Harkins can be reached at gina.harkins@military.com. Follow her on Twitter @ginaaharkins.

Read more: Here's the Latest on How Coronavirus Is Impacting Base Schools, Shopping