Poland will move thousands of troops toward its eastern borders in a historic realignment of a military structure built in the Cold War, the country's defense minister told The Associated Press on Monday.

Tomasz Siemoniak said the troops are needed in the east because of the conflict in neighboring Ukraine.

"The geopolitical situation has changed, we have the biggest crisis of security since the Cold War and we must draw conclusions from that," Siemoniak said.

He said that at least three military bases in the east will see their populations increase from the current 30 percent of capacity to almost 90 percent by 2017, and that more military hardware will be moved to those bases as well.

He said it was not some "nervous or radical move" but that because of this "situation of threat we would like those units in the east of Poland to be more efficient."

Although Poland joined NATO in 1999, most of Poland's 120,000-member army is based along the country's western border, as a relic of its former status as a Soviet Bloc member.

The units in the east, like the air defense unit in Siedlce, have only 30 percent of jobs filled in line with a plan that calls for 100 percent of troops "only in the case of war."