"Abbas has demonstrated that he's somebody who wants to work toward a two-state solution" to the Middle East conflict, White House spokesman Tony Snow said at a news briefing.

"I think it's important for Palestinians to wrestle with the issue of whether they want to have a two state solution," Snow said.

Abbas intends to call a referendum on a proposal developed by prisoners for a unified Palestinian political program that the governing Hamas faction opposes.

Abbas said Monday that he considered the referendum on a proposal to set up an independent Palestinian state alongside Israel "the way to overcome the ongoing crisis."

The referendum is expected to be called for July and will be seen as a vote of confidence in Hamas, which won legislative elections in late January but has been isolated internationally and financially because of its refusal to recognize the right of Israel to exist, to sever violence and to accept previous Israeli-Palestinian agreements.