The White House credited Israeli Prime Minister Ariel Sharon (search) with taking significant steps toward peace with the Palestinians on Thursday but said it would oppose any effort to simply impose a Mideast settlement.

Giving a major Sharon speech mixed reviews, presidential spokesman Scott McClellan urged the Israeli leader and Palestinian Prime Minister Ahmed Qureia (search) to meet face-to-face "very soon" and without preconditions to discuss how to move forward on a U.S.-endorsed road map for peacemaking.

"We believe that the road map is the way to get to the president's two-state vision" of a democratic Palestinian state existing alongside Israel by 2005, McClellan said.

In cautioning Israel against unilateral moves — unless they implemented the road map and contributed to peacemaking — McClellan said, "The United States believes that a settlement must be negotiated and we would oppose any Israeli effort to impose a settlement."

President Bush's spokesman noted that Sharon, in his speech Thursday in Herzilya, a suburb of Tel Aviv, spoke of Israel acting alone to end the half-century Mideast dispute only if peacemaking was stalled by the Palestinians.

"We are continuing to work hard with Israel and the Palestinians to make progress on the road map," McClellan said. "And we don't think it is best at this point to be discussing now what to do if progress is not made."

The spokesman praised Sharon's endorsement of the road map, his call for removing unauthorized outposts on the West Bank and his pledge not to build new Jewish settlements.

That would be consistent with the blueprint developed by the United States, the United Nations, the European Union and Russia, McClellan said.

He also praised Sharon's promise to halt special economic incentives for Israelis to settle on the West Bank and in Gaza.

On another touchy issue, McClellan reiterated U.S. concerns about Israel's construction of a security barrier, which Sharon said would be speeded up as a prospective, easily defended border with the Palestinians.

"We oppose a route that interferes with the normal Palestinian life or makes building a viable Palestinian state impossible," McClellan said.

"We have said that the fence should not be or appear to be a pretext for taking land, and it should not be something that presses undue burdens on the Palestinian people," he said.

And yet, McClellan said, "it's not that we necessarily oppose construction of the fence."

The White House spokesman also renewed Bush's insistence that the Palestinians take firm steps against terror and dismantle terror groups.

Rep. Brad Sherman, D-Calif., said, "The world should appreciate and the U.S. should reward the willingness of the Israelis to make unilateral concessions."

"Sharon is proving Israel's dedication a two-state solution," he said in a statement.

By contrast, Americans for Peace Now (search), said, "Any disengagement plan based on the current route of the security barrier amounts to annexation, not separation."

Debra DeLee, president of the private group, said the security barrier was being built in a way that cuts deeply into the West Bank, bringing thousands of Palestinians inside Israel's line of defense, escalating construction costs and imposing a heavy burden on the Israeli Defense Force.

As for Sharon's offer to remove some settlements, DeLee said the prime minister had made similar promises in the past but not followed through.