Prime Minister Binyamin Netanyahu refused to make any commitments concerning settlements during his first official trip to Washington, even though a construction freeze is a top US demand. Netanyahu was taken to task by a top US senator on Tuesday - his final day here - over the issue of settlements, even as the prime minister tried to emphasize that there was wide agreement between the two countries on major Middle East issues. Yet he would not commit to removing outposts or freezing natural growth, despite knowing that Washington believes halting settlements to be a key issue. John Kerry, chairman of the Senate Foreign Relations Committee, began his remarks following his meeting with Netanyahu by saying, "I emphasized to the prime minister the importance of Israel moving forward, especially with respect to the settlements issue." On Monday, US President Barack Obama treaded more lightly on the settlement issue, but still stressed that such construction must end. "Settlements have to be stopped in order for us to move forward," he said alongside Netanyahu in the Oval Office. "That's a difficult issue. I recognize that, but it's an important one, and it has to be addressed." Netanyahu, though, indicated that any actions vis-Ã¡-vis settlements would only be taken after the two countries dealt with the issue in-depth - it is expected to be a major component of talks with envoy George Mitchell once he sets up an office in Jerusalem next month - and that Israel wanted to see what it was receiving in return. The process of "defining terms" is expected to begin immediately, as Israel is looking to clarify a number of non-written understandings with the Bush administration, the main parameters of which were that Israel would restrict construction to the large settlement blocs within the lines of the existing settlements. Israeli sources said, however, that Netanyahu had made clear that Israel could not be expected to unilaterally fulfill its part of the road map while the Palestinians were not obliged to do the same. According to Netanyahu's interpretation, the world cannot say that Israel, as stipulated under the road map, needs to freeze all settlement construction, including for natural growth, while at the same time not demanding that the Palestinians uproot terrorist infrastructure, as is also required by the road map. During various meetings in Washington, Netanyahu made clear his position that Israel had gone beyond the call to merely freeze settlement construction, and had actually uprooted settlements during the disengagement from Gaza. The Palestinians, he argued, not only had not uprooted the terrorist infrastructure, but as a result of the disengagement, had turned Gaza into a terrorist base against Israel. During the talks in Washington, Netanyahu also repeated a number of times that Israel was willing to begin negotiations with the Palestinians "immediately," and that what was holding up a renewal of the talks was not Israel, but the Palestinian Authority. Uzi Arad, a top Netanyahu aide and head of the National Security Council, said that the Palestinians had placed unhelpful preconditions on the talks. "Israel is willing to enter negotiations with the Palestinians with the best intentions," he said late Monday. "One expects the same from the Palestinians. One does not expect the establishment of preconditions that will take us further away from negotiations." The Palestinians have stated that they will only resume negotiations after Israel commits itself to a two-state solution and ends settlement construction. Speaking to Israeli reporters after his meeting with Kerry, Netanyahu said that the key issue related to the Israeli-Palestinian peace process to emerge during his talks in Washington was the importance American officials were placing on Arab states playing a role. "The new thing here is that President Obama says that not only Israel must give, but also the Palestinians and the Arab sates, and not at the end of the process, but now. They must take concrete steps to improve relations with Israel and begin to move forward with reconciliation," he said. That idea was echoed by Kerry, who said Tuesday that "this is not a one-way street. The burden is not only on Israel to take all the... steps." He said it was "vital that the Arab community takes steps to indicate its willingness to contribute," specifying that it must do so not only in relation to Israel, but also to the Palestinians and their rejectionist groups in Gaza and Lebanon. Netanyahu emphasized, at the Kerry meeting, the threat of Iran and again rejected the idea of linking the issue to the Israeli-Palestinian conflict, while noting that he would like to see progress on both fronts. "We intend to pursue the peace track independently of what happens in Iran, but in point of fact... it should be done in parallel," he said. Israel and America have been disagreeing over how to prioritize the issues, with Israel urging action on Iran first and the US stressing how progress with the Palestinians could aid the struggle to keep Iran from going nuclear. Israel has also wanted to see the US impose a tight timeline on negotiations with Iran over its nuclear program, worrying that talks would allow Teheran to run out the clock. Israeli officials have suggested that three months would be a sufficient time frame for engagement efforts, but Obama rejected "artificial deadlines" at the joint press conference Monday. He did, however, offer a time frame of his own, suggesting that the emerging US policy of diplomatic engagement - which he indicated would begin in earnest after Iran's June elections - would be reassessed at the end of the year. "The important thing is to make sure that there is a clear timetable, at which point we say these talks don't seem to be making any serious progress," Obama said. "By the end of the year, I think we should have some sense as to whether or not these discussions are starting to yield significant benefits, whether we're starting to see serious movement on the part of the Iranians." Channel 2 reported Tuesday night that Netanyahu told Obama he wouldn't launch an attack on Iran before then, but Israeli officials are strongly denying the reports. Netanyahu made clear after meeting with the president that Israel retained the right to defend itself. Speaker of the US House of Representatives Nancy Pelosi, who met with Netanyahu after Kerry did, also stressed the importance America put on the Iranian issue. "The question of Iran is one that is of concern to us in Congress. Certainly it is to Israel because of its proximity, but it is an issue for the world," she said. "It is important for all of us to work together to be sure that Iran does not develop a weapon of mass destruction." Netanyahu, speaking to Israeli reporters, said he had come away from his White House meeting reassured by what he had heard on Iran. "Israel and many of our Arab neighbors understand the threat posted by Iran's quest to develop nuclear weapons capability," he said. "I was assured yesterday by President Obama that the United States is continuing to prevent that from happening, and I think that is important not only for security, but for peace." Secretary of State Hillary Clinton also addressed the settlement issue at a press conference on Tuesday. "I think the President was very clear yesterday in his statement that he wants to see a stop to the settlements," she said. "I hosted a dinner for Prime Minister Netanyahu later in the day at the State Department, and we reiterated that that is the position and policy of the United States Government." She said the US was committed to a two-state solution, and "obviously, underlying that commitment is the conviction that the Palestinians deserve a viable state. And therefore, nothing should be done to undermine the potential resolution of the peace effort that could prevent such a two-state solution from taking hold." Clinton reiterated that "we are, as always, committed to the safety and security of Israel, but our goal is to see the people living together."