Egypt's announcement that it will open a key border crossing with the Palestinian Gaza Strip within days sparked concern in Israel on Friday and revealed how the upheaval in the Arab world is shifting the Mideast conflict. Under former President Hosni Mubarak, Egypt restricted the movement of people and goods through the Rafah crossing in keeping with a blockade it imposed on Gaza along with Israel. The restrictions were aimed at weakening the Hamas militants who rule the Gaza Strip, and whom both Egypt and Israel saw, until recently, as a common enemy. After Mubarak's ouster in February by a popular uprising, Egypt's new transitional Cabinet and ruling military council are taking a cooler line toward Israel and the U.S. Egypt has also been warming its ties with Israel's enemies, chiefly Hamas and its main backer, Iran. Egypt's new foreign minister, Nabil al-Araby, said Thursday that the closure was about to end, calling the decision to close the crossing "a disgusting matter" in an interview with the Arab satellite channel Al-Jazeera. Al-Araby said the crossing would be opened "in the coming days." Israeli officials would not comment publicly Friday, but Israel is "troubled by recent developments in Egypt," an Israeli government official said. He spoke on condition of anonymity because there had been no official comment. Israel views the Gaza blockade as essential to minimizing the flow of weaponry and militants into the territory, where Palestinian squads regularly launch rockets at Israeli towns, and to pressuring Hamas. "In the past, despite efforts by the Egyptian government, Hamas succeeded in building a formidable military machine. If those efforts were to cease, how much easier would it be for Hamas to build a terrorist military machine," the official said. The decision appeared linked to the surprise announcement one day earlier that the two rival Palestinian factions, Hamas and Fatah, had signed a reconciliation agreement brokered by Egypt. The deal is scheduled to be signed on Wednesday in Cairo, Palestinian Authority spokesman Nabil Abu Rdeneh said Friday. It is to lead the way to a transitional unity government and elections. That announcement was also greeted with dismay in Israel, which said it ruled out any chance of peace talks with a Palestinian government that includes the Hamas militants. Hamas, which rejects peace talks and is committed to Israel's destruction, is considered a terrorist organization by Israel, the U.S., the European Union and others. The announcement on the border crossing also appeared to reflect a responsiveness by Egypt's new military rulers to street sentiment hostile to Israel and to the U.S. A recent poll showed more than half of Egyptians favor an annulment of the 1979 peace treaty with Israel. The number of travelers currently crossing through Rafah is limited to approximately 300 a day and is subject to Egyptian security clearance that is often withdrawn. The other crossings available to Gaza's 1.5 million people are with Israel and are closed with few exceptions, such as emergency medical cases. Israel allows goods into Gaza with restrictions on construction materials it says could be used by militants. In Washington, Jake Sullivan, the State Department's director of policy planning, said the U.S. would continue to work with Egyptian authorities on ensuring that weaponry and other material cannot cross the Gaza border. He said he could not comment on the changes in Egyptian policy. The Israeli official said Friday that Israel was concerned about calls in Egypt for the abrogation of the three-decade-old peace agreement between the countries, by "the rapprochement between Egypt and Iran, and by the upgrading of the relations between Egypt and Hamas." Hamas hailed the move. Taher Nunu, a Hamas spokesman, said Hamas "has received positive signals from Egypt about the mechanism that Egypt is going to adopt in the terminal," and has been informed by the Egyptians that "all future progress on Egypt's part is going to serve the interests of the people of Gaza." Before the blockade was imposed, the crossing was supervised by a detachment of European observers known as EUBAM that was meant to block the movement of weapons and other contraband through the terminal. The new details of the crossing's functioning, including the role of the European observers, remains unclear. Benoit Cusin, a EUBAM spokesman, said Friday that he was aware that discussions were ongoing among "Egypt and other parties" but that there had been "no decision on redeployment of EUBAM monitors." The decision by Egypt marks a further cooling of ties with Israel. The peace agreement between the two countries, in return for which Egypt received the captured Sinai peninsula back from Israel and significant military and economic assistance from the U.S., has anchored regional stability for more than three decades. This week's unity deal between Hamas and Fatah drew praise from Iran. The official IRNA news agency quoted Ali Akbar Salehi, the foreign minister, expressing hope the deal could accelerate "achieving great victories in confrontation with occupiers," meaning Israel.