Hamas is not the only Palestinian party that would reject any U.S.-sponsored agreement. Most of the Palestinian groups...have already expressed their opposition to the Israeli-Palestinian peace talks.

Kerry needs to listen to what Hamas and other groups are saying in Arabic.

As U.S. Secretary of State John Kerry pursues his efforts to reach a peace agreement between the Palestinian Authority [PA] leadership and Israel, Hamas reaffirmed that it would not honor any deal that does not meet its goals.

The Hamas announcement serves as a reminder that any US-brokered deal between Israel and the PA will not mean the end of the conflict.

In fact, PA President Mahmoud Abbas is not in a position to sign any document that calls for an end to the conflict with Israel.

Abbas has no control over the Gaza Strip, which has been under the rule of Hamas since the summer of 2007. Any agreement he signs with Israel would only apply to those areas under the control of the PA, in the West Bank or territories handed over to him by Israel.

U.S. Secretary of State John Kerry sits with PA President Mahmoud Abbas in Amman, Jordan, on June 28, 2013. (Image source: U.S. State Department)

Hamas is not the only Palestinian party that would reject any U.S.-sponsored agreement. Most of the PLO groups, including the Popular Front for the Liberation of Palestine and the Democratic Front for the Liberation of Palestine, have already expressed their opposition to the Israeli-Palestinian peace talks.

This is in addition to other radical Palestinian groups that do not belong to the PLO, first and foremost Islamic Jihad.

"The Palestinians are not bound by any agreement that results from the current negotiations [between Israel and the PA] and which harm Palestinian rights," said Hamas's top leader in the Gaza Strip, Mahmoud Zahar. "The Palestinian negotiators have no legitimacy and are not authorized to speak on behalf of the Palestinians."

Zahar claimed that Abbas and his Fatah faction were negotiating with Israel only because of American pressure and to ensure continued Western funding for the Palestinian Authority.

Even senior Fatah officials seem to agree with Zahar's assessment. Over the past few months, some of these officials, such as Sufian Abu Zaida, Hussam Khader and Mohammed Dahlan, have not hesitated to come out in public against the peace talks and any future agreement with Israel.

Given Hamas' announcement that it would not honor or recognize any deal signed between the PA and Israel, Kerry needs to take into account that any peace agreement will not put an end to the conflict.

In the future, Hamas and the other rejectionist groups will say that Abbas did not have a mandate from his people to sign an agreement with Israel.

"The Palestinians have reached a level of awareness where they would not allow anyone to decide their fate," Zahar explained, referring to the ongoing negotiations between the PA and Israel. "The talks are continuing and if we don't do anything now, we could end up with an Oslo Two Accord."

Hamas and its Palestinian allies will in any case never accept Israel's right to exist. So even if Abbas today gets 100% of the West Bank, Gaza Strip and east Jerusalem to establish a Palestinian state, Hamas, which represents a substantial part of the Palestinian population, will continue to fight to "liberate the rest of Palestine."

As Zahar stated, "Our battle is not outside Palestine. Rather, it is inside Palestine. Our program is to liberate Palestine."

Kerry needs to listen to these voices and take them into account as he continues to talk about a peace agreement between Israel and the Palestinians. It is not enough to listen to what Abbas and chief PLO negotiator Saeb Erekat are telling him in English. Kerry needs to listen to what Hamas and other groups are saying in Arabic.