SOFIA, Bulgaria-Bulgaria signed a series of defense agreements with the United States on Thursday as part of a 10-year deal allowing U.S. troops to be deployed in the former Warsaw Pact country, the Defense Ministry said.

The overall deal, signed in 2006, is seen as part of a broader U.S. military strategy of shifting troops based in Europe further east to small, flexible bases closer to potential hotspots in the Middle East. It will see up to 2,500 U.S. troops deployed in Bulgaria.

Bulgarian officials have said the deal will help improve Bulgaria's armed forces, boost its economy and enhance security.

The eleven agreements signed Thursday concern customs procedures, the hiring of local contractors, environmental protection, tax issues, supplies and security, among others, the Defense Ministry said in a press release.

One more agreement must be signed, concerning logistics, but the details are still being worked out, the ministry said.

The U.S. is interested in small, flexible bases, different from those set up to house large numbers of troops during the Cold War. The locations are a training area in Novo Selo, the Bezmer and Graf Ignatievo air bases and storage facilities near Aitos.

The Defense Ministry quoted U.S. Ambassador John Beyrle as saying U.S. Congress has allocated more than US$60 million for construction in Novo Selo, and that the first U.S. military contingent is expected to arrive in Bulgaria in the fall.