The Quartet is greatly concerned by Israel's recent announcements to advance planning for new housing units in Ariel and Easter Jerusalem, and reiterated its position in this regard, in particular its statement of March 12, 2010. The Quartet reaffirms that unilateral action by either party cannot rejudge the outcome of negotiations and will not be recognized by the international community. Jerusalem in particular is one of the core issues that must be resolved through negotiations between the parties, which underscores the urgent need for the parties to resume serious and substantive talks. This comes at a critical juncture with Quartet efforts ongoing to resume negotiations which are the only way to a just and durable solution to the conflict. The Quartet is determined to pursue its efforts. Ultimately, it is up to Israeli and Palestinian leaders to make tough decisions and avoid actions by their governments that undermine the very goals they and we are trying to achieve.