Polish and US negotiators were wrapping up their latest round of talks Thursday on a proposed US missile defense base, and Poland's foreign minister said the two sides have narrowed their differences. Talks about a US plan to build a missile interceptor base in northern Poland have been dragging over Polish demands for additional security guarantees - demands now underlined by the fighting between Russia and Georgia. "Our positions have become closer," Foreign Minister Radek Sikorski said after meeting chief US negotiator John Rood late Wednesday. "There is a change in the US position," Sikorski said, without elaborating. "Poland is negotiating in good faith and an agreement is possible."