The Office of the Director of National Intelligence (ODNI) will begin calling more of its furloughed employees back into the office this week despite the ongoing partial government shutdown.

70% of the intelligence community has been furloughed as a result of the shutdown, leaving the leaders of all intelligence agencies scrambling to carry out their core missions.

Director of National Intelligence James Clapper issued a statement Wednesday telling employees he had "authorized the recall of some employees who perform functions that directly support efforts to protect against imminent threats to life or property, and help provide the President with the intelligence he needs to carry out his core constitutional functions related to national security."

Typically, the president receives a daily intelligence briefing in the morning hours.

The CIA made a similar announcement earlier in the week, with CIA Director John Brennan saying in a letter to employees that "keeping our staffing at the dramatically reduced levels of the past week would pose a threat to the safety of human life and the protection of property."

Like Clapper, Brennan also cited the need to provide intelligence information to the president as a reason why more employees would be returning to work.

One U.S. intelligence official told CNN that managers at all agencies are currently "in the process of determining exactly who will be recalled under revised staffing plans" and said the process of determining who can be brought back into work "will continue over the coming days."

Clapper testified before the Senate Judiciary Committee last week, warning Congress the damage from the shutdown would be "insidious" on the intelligence community.

"Each day that goes by, the jeopardy increases. This is a dreamland for foreign intelligence services to recruit," he said.

Since the shutdown first took effect, various U.S. intelligence services have retained the right to call back essential staff in cases where it affected national security. This allowed for management to call in specific experts if, for example, there were reports of terrorist chatter that were particularly concerning.

But as the shutdown drags on with no clear ending in sight, leaders in multiple intelligence agencies are being forced to revise their plans and are recalling a wider circle of employees.

One intelligence official summed up the current situation, saying, "In the beginning of the shutdown, only those CIA employees working imminent threats were on the job. But it's been determined that the CIA not performing its core missions for an extended period of time itself presents the risk that real threats to our national security will go undetected."