WASHINGTON — While Palestinian Authority Prime Minister Mahmoud Abbas received the red-carpet treatment from the White House last week, he received a much cooler reception on Capitol Hill.

Abbas' first official trip gave the Palestinian leader an opportunity to thank President Bush for $20 million in direct aid and for the president's support for the prime minister's steps toward peace.

But in congressional meetings, Abbas faced sharp questions from lawmakers about his ability to lead, his efforts to date to combat terrorism and his criticisms of Israeli actions.

That is in sharp contrast to Israeli Prime Minister Ariel Sharon, whose meetings with lawmakers were limited this time around but who often receives warm welcomes from congressional leaders.

Sharon "gets a much warmer reception" and a "sympathetic ear," said Rep. Eliot Engel (D-N.Y.), a member of the House International Relations Committee's Middle East subcommittee.

He said lawmakers are sympathetic to Abbas because they see him as an alternative to Palestinian Authority President Yasser Arafat, but they have yet to see substance.

Many members of Congress support Sharon's anti-terrorism measures and his timetable for moving forward in the peace process.

So, for example, while Bush called on Sharon to keep in mind how his defensive measures affect the peace process — presumably referring to the fence Israel is building to keep out terrorists — some lawmakers wrote Bush on the eve of Sharon's visit to emphasize that how the fence is necessary for Israel's security.

Abbas spent considerable time on Capitol Hill during his first official visit last week.

He met with congressional leaders in the Senate and the House on July 24, presenting them with a wish list of ways to strengthen his government and promote the international "road map" for peace.

Among his requests was help to pressure Israel to release Palestinian prisoners, to reconsider the security fence and to allow Arafat freedom of movement.

"Abbas was businesslike," said a Democratic House aide. "He said, 'This is what I need and this is why I need it.'"

But while Abbas impressed some with what they called his straightforward responses, others said they were concerned about his reluctance to dismantle Palestinian terrorist groups.

Many in Israel believe that unless the groups are dismantled, they will use the three-month cease-fire to which they agreed to rebuild and expand their infrastructure, leading to an eventual escalation in attacks.

Sources say some lawmakers resented Abbas' ability to shift the focus in the conflict away from Palestinian reform toward issues such as Israel's building of a security fence.

Rep. Ileana Ros-Lehtinen (R-Fla.), chair of the Middle East subcommittee, called the meeting with Abbas "disappointing" because he provided "lackluster" answers to questions about his control over the West Bank and Gaza and his relationship with Arafat.

"He put his best case forward to the committee," she said. "I just don't know whether the answers were tough enough."

Despite the ambivalence expressed by many, one Democratic aide in the Senate said, "The view of most people was that Abbas is a smart guy and needs our support."

On Tuesday, Sharon was able to meet only with Senate leaders because the House of Representatives has already begun its summer recess.

One issue Congress may weigh in on when lawmakers return in the fall is the security fence issue, but it is not yet clear how.

The fence, which has been under construction for more than a year and which Palestinians oppose, has been making headlines mostly because Abbas appears to have gotten support for his view from Bush and White House National Security Adviser Condoleezza Rice.

While some lawmakers have already told Bush they support the fence, others remain concerned about its impact. Over the last month, Palestinians have been circulating a multimedia presentation to Washington insiders — including Rice — about the fence's effect on Palestinian living conditions.

Israel says the fence is necessary to keep out suicide bombers, but the Palestinians worry that it is setting a de facto border between Israel and the Palestinians.

Engel said that when Abbas compared the fence to the Berlin Wall, lawmakers countered that the Berlin Wall kept people in, while the Israeli fence keeps people out.