The U.S. State Department is condemning an Israeli decision to expand the boundary of an existing West Bank settlement bloc.

Spokesman John Kirby said Friday that the move "undermines the possibility of two state solution."

Last month, Israel's defense ministry added a compound in the West Bank to the jurisdiction of the Gush Etzion regional council. The compound is located south of a junction in the West Bank that has been the scene to multiple attacks by Palestinians.

The Palestinians claim the West Bank, along with east Jerusalem, as parts of their future state. They consider all Israeli construction there to be illegal — a position that is backed by the international community. Israel says settlements along with other core issues like security should be agreed upon in peace talks.