Stoltenberg will visit the NATO Force Integration Unit today that is similar to ones that will be built in Poland, Bulgaria and the three Baltic states - Estonia, Latvia and Lithuania.
He met Defence Minister Mircea Dusa yesterday and later will tour the site of the facility with President Klaus Iohannis.
The alliance says the six small headquarters will be ready by the end of the year and will each have a staff of 40 people who participate in exercises and can facilitate rapid deployment of forces to the region if needed.