US special envoy to the Middle East, Jason Greenblatt, responded Thursday morning to the recently-struck Palestinian unity deal, backing up Israel in its stance on the matter. "All parties agree that it is essential that the Palestinian Authority be able to assume full, genuine, and unhindered civil and security responsibilities in Gaza and that we work together to improve the humanitarian situation for Palestinians living there," Greenblatt wrote. "The United States reiterates the importance of adherence to the Quartet principles: any Palestinian government must unambiguously and explicitly commit to nonviolence, recognize the State of Israel, accept previous agreements and obligations between the parties – including to disarm terrorists – and commit to peaceful negotiations. If Hamas is to play any role in a Palestinian government, it must accept these basic requirements."Israel's security cabinet announced earlier this week that it would not negotiate with a Hamas-run Gaza until the terror group answers a list of Jerusalem's demands.