Joe Biden, the US vice-president, has said that Israel should back a two-state peace agreement and stop constructing new Israeli settlements on occupied land.
In a speech to the American Israel Public Affairs Committee (Aipac), the pro-Israeli lobby group, Biden also called on the government of Binyamin Netanyahu, the Israeli prime minister, to ease restrictions on Palestinians.
Biden told Aipac delegates in Washington on Tuesday: "Israel has to work for a two state-solution.
"You're not going to like my saying this - but not build more settlements, dismantle existing outposts and allow Palestinians freedom of movement... and access to economic opportunity."
Netanyahu has so far shied away from publicly supporting a two-state solution to the Israeli-Palestinian conflict, an omission that has dismayed many US, Arab and European officials.
The US vice-president also said the US would never abandon its commitment to Israel's security, calling it "non-negotiable".
And he said the Palestinian Authority "must combat terror and incitement against Israel".
Biden's remarks went further than those made by Obama in a White House meeting last month with Jordan's King Abdullah, in which he repeated his support for a two-state solution.
His comments also came hours ahead of a meeting between Barack Obama, the US president, and Shimon Peres, Obama's counterpart.
In a speech by video-link to Aipac on Monday, Netanyahu said he was ready to begin Israeli-Palestinian peace talks immediately, but made no reference to a Palestinian state.