Earlier in the day, NATO said that AWACS surveillance jets were due to arrive in Romania some time on Tuesday to monitor Russia's military activity.
"AWACS jets arrived in Bucharest, from where they will transmit information to NATO about any tactical and operational movements on the alliance's border," Tilvar said.
NATO will trace military actions on its eastern flank using these aircraft, the minister added.
AWACS surveillance planes belong to a fleet of 14 NATO surveillance aircraft that are usually based in the western German town of Geilenkirchen.
NATO has been boosting its eastern flank on the border with Russia and Belarus since late 2021 by dispatching additional troops. In response to Moscow launching a special military operation in Ukraine in February 2022, NATO has further reinforced the flank by sending additional ships, planes and ground troops to the region and putting them on high alert. The alliance also stated that the AWACS systems were capable of detecting jets at a distance of hundreds of miles, which made them a key element in NATO's deterrence and defense. The mission is scheduled to last several weeks.