SHARM EL-SHEIKH, Egypt – An Egyptian security official declared the blockade of Gaza a failure Monday and said his country will keep its border with the Palestinian territory open indefinitely.

Keeping that crossing point open long term would ease the blockade imposed by Israel three years ago to isolate and punish Gaza’s Hamas rulers. It also restores a link to the outside the world for some of Gaza’s 1.5 million Palestinians.

Egypt opened its border with Gaza soon after Israel’s deadly raid on an international flotilla of activists trying to break the blockade a week ago. Israel has not publicly protested the Egyptian move, but officials declined to comment Monday.

In another escalation of the tension off Gaza, Israeli naval forces shot and killed four men wearing wet suits on Monday, and the militant group Al-Aqsa Martyrs’ Brigades said they were members of its marine unit training for a mission.

Vice President Joe Biden said Monday the U.S. is closely consulting with Egypt and other allies to find new ways to “address the humanitarian, economic, security and political aspects of the situation in Gaza.” He issued the statement after meeting Egyptian President Hosni Mubarak in the Egyptian Red Sea resort of Sharm El-Sheikh.

Egypt’s measures up to now constitute an incremental change rather than a radically different approach to the border closure. It appeared aimed, in part, at defusing some of the anger in the Arab and Muslim world over Egypt’s role in maintaining the blockade.

For the time being, Egypt is only allowing a very restricted group of Gazans to leave the territory, including medical patients and those with residency abroad. In keeping the passenger terminal in the border town of Rafah open continually, rather than sporadically as before, Egypt is helping reduce the backlog of Gazans with the required permits waiting to get out.

Egypt and Israel have maintained the blockade since Hamas took control of Gaza in 2007, with Israel calling it a key measure to stop weapons from reaching Hamas militants, who have hit southern Israel with rockets and in past years killed hundreds in suicide bombings.

The Egyptian security official said, however, that the closure has failed to achieve its goals, including the release of an Israeli soldier held by Hamas since 2006. Israeli airstrikes and Egyptian security efforts have also yet to choke off a bustling smuggling trade that uses hundreds of tunnels along the Gaza-Egypt border.

Under the restrictions at the Rafah crossing point, Egypt is letting in some humanitarian aid but will not transfer large cargo shipments or construction material because the terminal is designed primarily as a crossing for travelers, said the Egyptian official, who spoke on condition of anonymity because of the sensitivity of the issue.

For its part, Israel allows through only basic humanitarian goods, blocking crucial items like cement needed to rebuild war damage because it argues the material could be used by Hamas. The closure has crushed Gaza’s already fragile economy.

The Egyptian official said Israel must work out a new policy to end the suffering of the Palestinians while keeping pressure on Hamas.

Like Israel, Egypt also fears sharing a border with a slice of territory controlled by Islamic militants backed by regional rival Iran. Concerned about the flow of weapons, Egypt late last year began building an underground, metal barrier to seal the smuggling tunnels.

“We have a constant security concern, because Iran has its aims, Hezbollah has its aims, Hamas has its aspirations and aims, and al-Qaida can very well be present in Sinai and Gaza,” the official said.

The official called it a “continuously embarrassing situation” for Egypt and blamed Israel for thinking the closure could pressure Hamas to release the captured soldier, Gilad Schalit, or to abandon its extremist ideology.

In Monday’s clash, the Israeli military said a naval force spotted the Palestinians in the water and opened fire, preventing an attack on Israeli targets.

Al-Aqsa Martyrs’ Brigades , the violent offshoot of Palestinian President Mahmoud Abbas’ Fatah faction, claimed the four killed were training.