U.S. President Barack Obama is calling on Israel to stop construction of Jewish settlements in the West Bank. In a speech at Cairo University, Mr. Obama says the building of settlements is undermining efforts to achieve peace between Israel and the Palestinians. Mr. Obama's latest remarks highlight a growing rift between Israel and the United States.

President Obama used unusually blunt language in calling on the Israeli government to stop expanding Jewish settlements in the West Bank.

"The United States does not accept the legitimacy of continued Israeli settlements," said President Obama. "This construction violates previous agreements and undermines efforts to achieve peace. It is time for these settlements to stop."

Mr. Obama discussed the settlement issue during a meeting at the White House last month with Israeli Prime Minister Benjamin Netanyahu.

Since then top administration officials, such as Secretary of State Hillary Clinton, have used increasingly strong language to describe the president's policy.

"With respect to settlements, the president was very clear when Prime Minister Netanyahu was here," said Secretary Clinton. "He wants to see a stop to settlements - not some settlements, not outposts, not natural growth exceptions."

Nearly 300,000 Israelis live in about 120 Jewish settlements in the West Bank, among a Palestinian population of about 2.5 million. Many countries consider the settlements a violation of international law.

Despite the unusual U.S. pressure, Mr. Netanyahu says construction will continue in existing settlements to accommodate what the Israeli government calls "natural growth." The Israeli prime minister calls U.S. demands "unreasonable."

Israeli Cabinet Minister Benny Begin, who refers to the West Bank by its biblical name - Judea and Samaria, calls natural growth a legitimate reason for settlement building there.

"It applies the right of the Jewish people to its homeland, not only near Tel Aviv and Haifa, but also in the cradle of our history, in Samaria and in Judea," said Benny Begin.

President Obama is also at odds with Mr. Netanyahu over the ultimate solution to the Israeli-Palestinian conflict.

"The only resolution is for the aspirations of both sides to be met through two states, where Israelis and Palestinians each live in peace and security," said Mr. Obama.

Although Mr. Netanyahu says he is prepared to resume peace talks with the Palestinians, he pointedly stops short of endorsing Palestinian statehood.

Philip Wilcox, the president of the Foundation for Middle East Peace and a former U.S. Consul General in Jerusalem, says the basic policy differences between America and Israel are clear.

"The Netanyahu visit did not accomplish what the president had hoped," said Philip Wilcox. "The prime minister was quite firm in saying no to both of the president's requests, support for two-state peace and a freeze on Israeli settlements."

In addition to meeting with Mr. Netanyahu, President Obama also held talks last month with Palestinian President Mahmoud Abbas.

Ghaith al-Omari, a former top aide to the Palestinian president who is now with the American Task Force on Palestine, says the Obama administration is seeking concessions from the Israelis in an effort to increase Palestinian support for Mr. Abbas.

"They understand that Abbas needs a political deliverable," said Ghaith al-Omari. "They understand that Abbas' popularity is very much linked to the credibility of the peace process. Unless he can go to his own public and say that I have delivered something political, leading us towards liberation, he will continue to be weak no matter how much money we pump into the West Bank. So I think the first dimension is to strengthen Abbas politically and this is where I see the settlement freeze fitting very nicely."

The Israeli government says it will not build any new settlements and will remove small Jewish outposts in the West Bank.

M.J. Rosenberg, the director of policy analysis for the Israel Policy Forum, says Mr. Obama's demand for a settlement freeze is a strong signal that America wants to be perceived as an honest broker in the peace process.

"I mean right now there is a crisis, Israelis perceive it as a crisis, in U.S.-Israel relations over a settlements freeze and I think most Israelis are saying what, is that still around," said Rosenberg. "They do not even think about settlers. And when they think about the settlers they do not think about them in a positive way. In theory, in theory, it should not be that hard for a friendly American president who is pro-Israel, as Obama is, to make the case that dealing with this question and dealing with the settlers is in everyone's best interest."

Palestinian officials say they will not resume peace talks with Israel until the Netanyahu government agrees to a total freeze on construction in the settlements.

Ghaith al-Omari says he expects the Obama administration to remain firm on the issue.

"My own impression is that I see a seriousness that we haven't seen for a long time from the administration," he said. "I see diplomatic skill we have not seen for a while. I think the positions have been staked. The upcoming period is a period of seeing how good and how skillful U.S. diplomacy is."

Secretary of State Clinton says the Obama administration will soon present what she calls very specific proposals to Israel and the Palestinians on how to achieve a two-state solution to their conflict.

The U.S. is also expected to ask Arab states in the region for confidence-building steps with Israel to improve the atmosphere for negotiations.