Palestinian President Mahmoud Abbas snubbed Egyptian calls for his Fatah-led Palestinian Authority to dialogue with Hamas, and raised his tone against the Islamic movement for breaching the Egyptian border more than a week ago.

He described the blasting of the Rafah crossing wall and the flooding of half of Gaza's 1.5 million people into nearby Egyptian towns to stock up on badly-needed supplies as an "invasion."

Speaking to reporters in Cairo after meeting with Egyptian President Hosni Mubarak, Abbas said the PA was ready to assume control of the Rafah crossing only if it was in accordance with an international agreement signed when Israel withdrew from the Gaza Strip in 2005.

The agreement included European monitors and Israeli electronic surveillance of the crossing, which Hamas rejects as having turned Gaza into a prison that consolidated Israel's siege on the strip.

Abbas reiterated his conditions to dialog with Hamas on any issue: "Hamas has to retract its coup d'etat … accept the legitimacy [of the PA] and then hearts and minds would be open for dialogue. If not, dialogue with them will have no interest, will not be profitable."

Abbas has refused to speak to Hamas since it ousted the PA from the Gaza Strip in June, but Egyptian leaders had hoped he would be open to dialogue if only to resolve the border problem with Egypt.

For the first time since the Islamic group's takeover of Gaza, Cairo invited Hamas leaders to discuss how to control the Rafah border, which Egypt decided to keep open for a week to allow the Palestinians to buy food, medicine and fuel, before it began to close it again.

While Egypt rejected Hamas' control of Gaza and has kept its border closed, the dramatic breaking open of the border barrier has virtually compelled Cairo to recognize Hamas' rule over Gaza, analysts say.

Hamas political chief-in-exile Khaled Mishaal was due to arrive in the Egyptian capital on Wednesday to join a Hamas delegation from Gaza led by Mahmoud Zahar. Mubarak will not meet with them, in light of the U.S. rejection of Hamas as a "terrorist organization" and its historic links with Egypt's opposition Muslim Brotherhood.

Nevertheless, Mubarak has delegated his chief of intelligence General Omar Suleiman to speak to Hamas about the need for its cooperation in "putting the interests of the Palestinian people first," according to an Egyptian diplomat.

But Hamas officials were as adamant in their position as Abbas, with both sides claiming legitimacy and having their own version of who is fit to serve Palestinian interests.

Hamas spokesman Sami Abu Zuhri said the Rafah crossing "must be under Egyptian and Palestinian control only," and called for a "new arrangement that serves the higher interests of our people … without interference from any foreign power, whether American or European."

And speaking to reporters as he crossed into Egypt, Zahar, who lost two sons by Israeli fire, said a partial role for Hamas "contradicts reality. The reality is that there is a legitimate government and we will not give up our legitimacy to anybody."

Meanwhile, Egypt, which has a peace treaty with Israel, is stuck between a rock and a hard place as it tries to find a formula between international agreements on the Gaza crossings that gives the PA control, and the reality on that ground that cannot ignore Hamas' existence.

Independent Palestinian analysts say Hamas has imposed itself as a force that should be reckoned with. Other than the fact that it came to power by an overwhelming election victory in January 2006, breaking down the wall that separates it from Egypt was a clear defiance to Israel's siege on Gaza and the Western isolation of the Hamas-run strip.

Arab commentators say Hamas succeeded in challenging the legitimacy of the Western-backed PA in Ramallah by showing it has the ability to change the reality on the ground, where Abbas' authority has failed.

They add that the Egyptians, perhaps much to their dismay, were the first to recognize Hamas' weight, as Cairo seeks to secure the borders with Gaza, which was under its control when Israel captured it in 1967, and is apparently dreading the idea of assuming administration again.

Thus, Cairo's only hope to resolve the border crisis with Gaza is to push for a factional Palestinian dialogue that would lead to an agreement that unlocks the gates of Gaza's confinement – and then sell it to Israel and the United States.