WASHINGTON, Oct. 25  -- The U.S. Department of Defense said Monday that all 133 of its Cyber Command's Cyber Mission Force teams have achieved what it called "initial operating capability."

The Pentagon said in a statement the U.S. Cyber Mission Force reached the "milestone" on Friday, the day a massive cyberattack involving hijacking millions of webcams and other Internet-connected devices by hackers stopped or slowed access to major U.S. websites such as Twitter and Paypal.

Initial operating capability means that all Cyber Mission Force units can "execute their fundamental mission," the department explained, "It reflects a team's overall progress toward achieving full operational capability and serves as standard baseline in building the 133 teams."

According to the Pentagon, the Cyber Mission Force currently comprises about 5,000 individuals across the 133 teams but the goal is for the force to grow to nearly 6,200 by the end of the fiscal year 2018.

It quoted Michael Rogers, commander of the U.S. Cyber Command and director of the U.S. National Security Agency, as saying that the next major milestone is for all teams to be at full operational capability by Sept. 30, 2018, which means these teams will be "capable of operating at full mission capacity" by that time.

"Our experience is that it takes about two years to get a team from the time we stand it up to fully mission-capable," Rogers said.

So far, nearly half of the Cyber Mission Force teams had already achieved full operational capability, the Pentagon noted.

The U.S. Cyber Mission Force teams in development have already "played a vital role in supporting missions to safeguard the nation against cyberattacks since their inception in 2013," it said.

"We find ourselves in a situation -- a little unusual in the military arena -- wherein as soon as we get a basic framework, we have been deploying the teams and putting them against challenges," said Rogers.

According to the Pentagon, the U.S. Cyber Mission Force is made up of 13 national mission teams, 68 cyber protection teams, 27 combat mission teams and 25 support teams.