In comments released ahead of Abbas' first talks at the White House since being elected Palestinian president in January, Abbas said the current calm in the region would end unless peace talks with Israel are started.

"President Bush has supported our quest for freedom, as he made clear in his vision of a two-state solution to the Middle East conflict," Abbas said in a commentary published in the Wall Street Journal newspaper.

Abbas reaffirmed Palestinian support for the proposal but said: "It is also, however, a vision that is under attack.

"Every day Israel is undertaking steps that undermine President Bush's vision and effectively preclude a two-state solution to the Israeli-Palestinian conflict."

The Palestinian leader went on: "I am ready immediately to sit down with Prime Minister (Ariel) Sharon and start permanent peace negotiations. When I meet with President Bush today I will ask him to fulfil his vision of two sovereign, viable democratic states, living side-by-side in peace and security.

"If President Bush is still convinced and committed to his original vision, as I hope he is, and if Prime Minister Sharon is pressed to abandoned a unilateral solution, we can together make 2005 the year of peace in the Middle East."

Abbas highlighted Israel's settlement construction in the West Bank and its separation barrier, which he said was "suffocating Palestinian cities and towns," and accused Israel of seeking to cut off East Jerusalem from the rest of the West Bank.

He said these actions would, "if allowed to continue, render a two-state solution to our conflict an impossibility. If the two-state solution dies, our democracy cannot be far behind, for democracy and freedom are intertwined: it is impossible to have one without the other."

Abbas thanked Bush for his efforts to spread democracy throughout the Middle East but said: "I now call on him to help us, in dialogue with Israel, fulfil our dream of freedom."

Highlighting a virtual ceasefire that has held for four months, Abbas declared "this period of calm will be quickly undermined if peace talks are not immediately launched. If we are to save the vision of a two-state solution, Israel's evacuation from Gaza must be seen as a first step.

"It must be quickly followed by other steps in the West Bank as well as the resumption of peace talks aimed at a permanent peace agreement."

Abbas said that many Israeli actions contradicted his negotiating stance of a return to 1967 borders, the sharing of Jerusalem, a settlement of the Palestinian refugee problem and a permanent peace treaty.