The US State Department implemented a brief, planned outage of its unclassified networks over the weekend to install security improvements in an effort to bolster its protections against cyber attacks.
The government agency - which is responsible for the foreign policy of the United States - closed down its unclassified email systems in November last year after they were breached, allegedly by Russian hackers, a month before.
Repairs and disinfection work in November was completed to rid the mail servers of unnamed malware, and the State Department is now implementing security improvements to its unclassified networks to protect against future cyber attacks.
While detail of the security improvements were not released, a State Department spokesperson said the agency was working around the clock with experts from other government entities and the private sector to protect its data.
"We are simultaneously implementing a strategy to harden the department's infrastructure to better protect its data not only today and tomorrow, but well into the future," department spokesperson Jen Psaki said in a statement.
Psaki maintained there had been no compromise of core and classified State Department networks.
As of writing, the State Department internet-facing systems are back up again.