Speaking to ministers including Latvia's Raimonds Vejonis, NATO Secretary General Jens Stoltenberg said:
"The security environment continues to be challenging, both to the east and to the south.
"In Ukraine, the violence has sharply escalated. Russian-backed separatists are attempting to expand their territory in disregard of the Minsk agreements. And Russia continues to support them with training, forces and hundreds of pieces of advanced weapons - in breach of its international commitments.
"In North Africa and the Middle East, the international coalition has made significant progress. But violent extremism is spreading, with a terrible human toll. And this turmoil fuels terrorism in our own countries.
"As our security environment continues to change, NATO has to stay strong.
"Today, we will take the next steps in implementing the Readiness Action Plan to ensure our forces stay ready, robust and responsive. To deal with challenges on NATO’s borders from the east and from the south.
"This is the biggest reinforcement of our collective defense since the end of the Cold War," Stoltenberg said.
Part of the reinforcement will be the founding of six new command and control centers in Eastern Europe, including one in each of the Baltic states plus Poland, Romania and Bulgaria.
Allied to a new rapid reaction force headed by British troops, the Alliance hopes to greatly increase its ability to cope with sudden security situations in an effective and decisive manner.
"Latvia is ready to establish the necessary command entity and to provide the necessary support for its operation," Vejonis said after the meeting.
It has been a busy week for Vejonis, who ordered snap military drills on Wednesday and on Friday will be in Vilnius for a meeting of the Baltic Assembly which will discuss defense cooperation, joint military training, military procurement, as well as ways of countering Russia's "soft power" campaigns in neighboring countries.
"The situation in Ukraine has taught the Baltic countries a number of important lessons, and one of them is - we must join forces to combat the negative effects of soft power," Vejonis said.