NATO defense ministers decided on Thursday to send as much as 3,500 additional troops to Iraq.

-We will expand the NATO training mission in Iraq to ensure that ISIS doesn't return- the alliance's Secretary-General Jens Stoltenberg announced at a press conference.

The number of NATO personnel will be increased from the current 500 to 4,000 in the country, the NATO chief said after the virtual meeting's second day.

Noting that the ISIS/Daesh terror group still operates in Iraq, Stoltenberg said the "increase in attacks highlights the importance to increase the NATO mission."

He added that by expanding its capacity-building mission, the alliance aimed to avoid a situation in the future that would require NATO combat forces.

NATO defense ministers have yet to decide on the future presence of the military alliance in Afghanistan, Stoltenberg said.

-We want to make sure that we have a lasting political agreement that enables us to leave- he said.

The NATO chief stressed that the alliance seeks to ensure Afghanistan never again becomes a "safe haven for terrorists that would attack our homeland."