As Israel ordered a slight easing of its blockade of the Gaza Strip Wednesday, McClatchy obtained an Israeli government document that describes the blockade not as a security measure but as "economic warfare" against the Islamist group Hamas, which rules the Palestinian territory.

Israel imposed severe restrictions on Gaza in June 2007, after Hamas won elections and took control of the coastal enclave after winning elections there the previous year, and the government has long said that the aim of the blockade is to stem the flow of weapons to militants in Gaza.

Last week, after Israeli commandos killed nine volunteers on a Turkish-organized Gaza aid flotilla, Israel again said its aim was to stop the flow of terrorist arms into Gaza.

However, in response to a lawsuit by Gisha, an Israeli human rights group, the Israeli government explained the blockade as an exercise of the right of economic warfare.

"A country has the right to decide that it chooses not to engage in economic relations or to give economic assistance to the other party to the conflict, or that it wishes to operate using 'economic warfare,'" the government said.

McClatchy obtained the government's written statement from Gisha, the Legal Center for Freedom of Movement, which sued the government for information about the blockade. The Israeli high court upheld the suit, and the government delivered its statement earlier this year.

Sari Bashi, the director of Gisha, said the documents prove that Israel isn't imposing its blockade for its stated reasons, but rather as collective punishment for the Palestinian population of Gaza. Gisha focuses on Palestinian rights.

(A State Department spokesman, who wasn't authorized to speak for the record, said he hadn't seen the documents in question.)

The Israeli government took an additional step Wednesday and said the economic warfare is intended to achieve a political goal. A government spokesman, who couldn't be named as a matter of policy, told McClatchy that authorities will continue to ease the blockade but "could not lift the embargo altogether as long as Hamas remains in control" of Gaza.

President Barack Obama, after receiving Mahmoud Abbas, the head of the Palestinian Authority, said the situation in Gaza is "unsustainable." He pledged an additional $400 million in aid for housing, school construction and roads to improve daily life for Palestinians — of which at least $30 million is earmarked for Gaza.

Israel's blockade of Gaza includes a complex and ever-changing list of goods that are allowed in. Items such as cement or metal are barred because they can be used for military purposes, Israeli officials say.

According to figures published by Gisha in coordination with the United Nations, Israel allows in 25 percent of the goods it had permitted into Gaza before the Hamas takeover. In the years prior to the closure, Israel allowed an average of 10,400 trucks to enter Gaza with goods each month. Israel now allows approximately 2,500 trucks a month.

The figures show that Israel also has limited the goods allowed to enter Gaza to 40 types of items, while before June 2007 approximately 4,000 types of goods were listed as entering Gaza.

Israel expanded its list slightly Wednesday to include soda, juice, jam, spices, shaving cream, potato chips, cookies and candy, said Palestinian liaison official Raed Fattouh, who coordinates the flow of goods into Gaza with Israel.

"I think Israel wants to defuse international pressure," said Fattouh. "They want to show people that they are allowing things into Gaza."

It was the first tangible step taken by Israel in the wake of the unprecedented international criticism it's faced over the blockade following last week's Israeli raid on the high seas.

While there have been mounting calls for an investigation into the manner in which Israel intercepted the flotilla, world leaders have also called for Israel to lift its blockade on Gaza.

At his meeting with Abbas, Obama said the Security Council had called for a "credible, transparent investigation that met international standards." He added: "And we meant what we said. That's what we expect."

He also called for an easing of Israel's blockade. "It seems to us that there should be ways of focusing narrowly on arms shipments, rather than focusing in a blanket way on stopping everything and then, in a piecemeal way, allowing things into Gaza," he told reporters.

Egypt, which controls much of Gaza's southern border, reopened the Rafah crossing this week in response to international pressure to lift the blockade.

Egypt has long been considered Israel's partner in enforcing the blockade, but Egyptian Foreign Minister Hossam Zaki said the Rafah crossing will remain open indefinitely for Gazans with special permits. In the past, the border has been opened sporadically.

Maxwell Gaylard, the U.N.'s humanitarian coordinator in the Palestinian territories, said the international community is seeking an "urgent and fundamental change" in Israel's policy regarding Gaza rather than a piecemeal approach.

"A modest expansion of the restrictive list of goods allowed into Gaza falls well short of what is needed. We need a fundamental change and an opening of crossings for commercial goods," he said.

Hamas officials said that they were "disappointed" by Israel's announcement, and that the goods fell far short of what was actually needed.

"They will send the first course. We are waiting for the main course," Palestinian Economy Minister Hassan Abu Libdeh said in Ramallah, specifying that construction materials were the item that Gazans need most. Many Palestinians have been unable to build their homes in the wake of Operation Cast Lead, Israel's punishing offensive in the Gaza Strip in December 2008 and January 2009.

Israel said the cement and other construction goods could be used to build bunkers and other military installations.

Some of those goods already come into Gaza via the smuggling tunnels that connect it to Egypt.

(Frenkel, a McClatchy special correspondent, reported from Jerusalem. Warren P. Strobel and Steven Thomma contributed to this article from Washington.)