With the public spat between Jerusalem and Washington over construction in the settlements intensifying daily, US President Barack Obama dropped in unannounced on Defense Minister Ehud Barak while he was meeting National Security Adviser James Jones in the White House on Tuesday.

No details of the 15-minute conversation were provided, but it came following Obama's call Monday for a halt to all settlement construction, including for "natural growth." That was the first time Obama himself, and not an adviser or Secretary of State Hillary Clinton, had included "natural growth" in the settlement freeze.

Obama joined Barak's meeting with Jones at the very end.

While former president George W. Bush would often drop by in White House meetings that top Israeli officials were conducting with figures such as the vice president or national security adviser, Obama's visit was seen as particularly meaningful, as it came just a few hours before he was to set off for Saudi Arabia and then Egypt, and following several statements criticizing Israel for its settlement policy.

It was seen as an effort to show a balanced approach and give Israel a boost amid the US administration's outreach to the Muslim world, which will include a visit to Riyadh on Wednesday and a major speech in Cairo on Thursday, but no stop in Israel.

At the same time, the two countries have serious issues to discuss, including the settlement policy. In that context, Barak's role is particularly key, as he represents the left flank of Netanyahu's government and has a warmer following in Washington than some of his fellow coalition members, even as he has articulated a position supporting the prime minister's assertion that natural growth must continue.

The settlement issue was believed to have been one of the focuses of Barak's discussion with Jones. Following the meeting, Barak issued a statement saying that "the intimacy, openness and joint interests of Israel and the US are a foundation of Israeli policy, both in facing threats and making peace."

Barak's statement, however, could not camouflage deep differences that have been emerging over the settlement issue.

Officials in the Prime Minister's Office on Tuesday said that understandings on settlement construction with the US had formed the basis of Israel's acceptance of the road map in 2003 and the adoption of the disengagement plan in 2005, firing back at Washington for its demand for a settlement freeze that would include natural growth.

The implication of the officials' comments were clear: that if the US was changing its understandings on the settlements, it was undermining the foundations of the road map and was in essence reneging on understandings that were an essential part of Israel's decision to leave the Gaza Strip.

According to the officials in the Prime Minister's Office, "over the past decade, important understandings were reached on the issues of settlements, understandings that Israel abided by. While Israel committed itself not to build new settlements and to address the unauthorized outposts, there was an effort to allow for normal life in existing communities, especially those in the large settlement blocs that will definitely stay part of Israel in any final-status agreement."

According to those officials, the "overall concept was that neither Israel nor the Palestinians would take unilateral steps that would prejudge a final peace agreement. Those understandings reached between Washington and Jerusalem provided a crucial foundation for US-Israeli cooperation in the peace process.

"On the basis of these understandings, the government accepted the road map in 2003, and adopted the disengagement plan in 2005," the officials continued. "Israel will continue to abide by these bilateral understandings and seeks to strengthen them with the new US administration."

Dov Weisglass, who was intimately involved in reaching these understandings with the US, wrote in Yediot Aharonot on Tuesday that there was "no doubt" that the Bush administration recognized Israel's right to build within the construction lines of the settlements, on condition that no new settlements would be established, that there would be no expropriation of Palestinian land for the settlements and that no budgets would be allocated for encouraging settlement.

Officials in the Prime Minister's Office said there was concern that the US was now attempting to roll back those agreements.

That impression was strengthened by Obama's interview Monday with National Public Radio, in which he claimed to have "said very clearly to the Israelis, both privately and publicly, that a freeze on settlements, including natural growth, is part of those obligations [that Israel must fulfill]."

Although the US needed to maintain its "strong support" for Israel, Washington also had to be "honest" with Israel regarding the direction in which the region was heading, Obama added, three days before his address to the Arab world in Egypt.

"I don't think we have to change strong support for Israel," Obama said in the interview. "We do have to retain a constant belief in the possibilities of negotiations that will lead to peace, and that's going to require, from my view, a two-state solution."

Asked how he would reply to those in the Muslim world who felt the US blindly supported Israel, Obama replied, "Well, what I'd say is, there's no doubt that the United States has a special relationship with Israel. There are a lot of Israelis who used to be Americans. There [are] huge cross-cultural ties between the two countries. I think that as a vibrant democracy that shares many of our values, obviously we're deeply sympathetic to Israel."

And, he added, "I would also say that given past statements surrounding Israel; the notion that they should be driven into the sea, that they should be annihilated, that they should be obliterated - the armed aggression that's been directed toward them in the past - you can understand why not only Israelis would feel concerned, but the United States would feel it was important to back this stalwart ally."

However, Obama said, "Part of being a good friend is being honest, and I think there have been times where we were not as honest as we should be about the fact that the current direction, the current trajectory in the region is profoundly negative, not only for Israeli interests but also US interests. And that's part of a new dialogue that I'd like to see encouraged in the region."
Ehud Barak and Barack Obama...

Obama told NPR that "the United States has to follow through on what it says. It is important for us to be clear about what we believe will lead to peace - and that there's not equivocation, and there's not a sense that we expect only compromise on one side. It's going to have to be two-sided, and I don't think anybody would deny that in theory."

In the interview, Obama also intimated that if Hizbullah were to win the elections later this week in Lebanon, the US would possibly have to reconsider its policy toward the organization. The US has placed Hizbullah on its terrorist list, and has no contacts with the organization.