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), a pro-Israeli lobby group, Biden also urged the government of Benyamin Netanyahu, the Israeli prime minister, to ease restrictions on Palestinians.

"Israel has to work for a two state-solution," Biden told Aipac delegates in Washington on Tuesday.

"You're not going to like my saying this - but do 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.

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.

Commitment

Biden said Washington would never abandon its commitment to Israel's security, calling it "non-negotiable".

He also said the Palestinian Authority "must combat terror and incitement against Israel" and said the country's Arab neighbours would need to make "meaningful gestures" to Israel.

The vice-president'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.

Biden's comments also came hours before Barack Obama, the US president, met Shimon Peres, his Israeli counterpart, at the White House.

After the talks, Peres said that Netanyahu was committed to the so-called "road map" towards peace with the Palestinians.

"Mr Netanyahu said he will abide by the commitments of the previous government," he said.

"The previous government accepted the road map - in the roadmap you will find the attitude to the two state solution."

A White House statement after the talks said the two had talked about "the opportunities and challenges including the pursuit of a comprehensive peace in the Middle East and Iran's nuclear programme".

Iran 'danger'

At Tuesday's Aipac meeting, Biden addressed the issue of Iran and the Obama administration's diplomatic efforts.

"We are intensely focused on avoiding the grave danger ... of a nuclear armed Iran,"  he said.

"If our efforts to address this problem through engagement are not successful, we have greater international support to consider other options.

"Given the situation we inherited, we know we don't have unlimited time to make this assessment."

Aipac is lobbying for new US legislation that would tighten restrictions on Tehran by targeting firms that finance, ship or insure petrol exports to Iran.

Iran has continued its attempts to enrich uranium - a process which could be used to build an atomic weapons - despite three sets of sanctions being imposed by the UN security council.

Tehran says the process is part of a civilian nuclear programme, but Israel, the US and several Western allies say it could be a cover for building a weapon.