Jerusalem (CNN) Hamas should disarm and recognize Israel if it is to join a Palestinian unity government with rival group Fatah, the United States' Mideast envoy said Thursday. It's the first comment from the US following the landmark agreement between the two factions last week.

In a statement released Thursday, US Special Representative for International Negotiations Jason Greenblatt said Fatah, which controls the US-friendly Palestinian Authority, must "assume full, genuine and unhindered civil and security responsibilities" in Gaza, which Hamas controls.

"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," the statement reads.

Fatah's Azzam al-Ahmad (R) and Saleh al-Aruri (L) of Hamas shake hands after signing a reconciliation deal in Cairo.

Last week, the two long-time rivals reached a reconciliation agreemen t in a deal brokered by Egypt in Cairo. The accord handed control of Gaza to the Palestinian Authority, but made no mention of Hamas' weapons or military wing. It remains unclear how this issue will be resolved.

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