The US Department of State voiced on Tuesday its deep concern over latest reports of Israel's expansion of settlements, saying it was "surprised" by this announcement. "We are deeply concerned by these latest reports that over 20,000 additional units are in the early planning stages," Department Spokesperson Jennifer Psaki told reporters here. "We were surprised by these announcements, and are currently seeking further explanation from the government of Israel," she added. She stressed "our position on settlements is quite clear; we do not accept the legitimacy of continued settlement activity." Psaki noted "we've called on both sides to take steps to create a positive atmosphere for the negotiations."