The announcement was expected after Mr Abbas on Tuesday got the green light from the executive committee of the Palestinian Liberation Organisation (PLO) to hold a referendum asking Palestinians to vote on a plan for statehood alongside Israel.
The endorsement came despite fierce opposition from Hamas, which argued that more time was needed to resolve differences with Mr Abbas's own Fatah faction.
Hamas has rejected the statehood manifesto, which contradicts its policy of not recognising Israel, and says a referendum would be illegal so soon after the parliamentary election.
Mr Abbas’s spokesman Nabil Abu Rudeina said on Tuesday that a date for the referendum would be declared within 48 hours -- still leaving open the possibility of a last-minute compromise. He said the referendum would take place 40 days after the announcement.
’More talks needed’
However, there was little expectation that Hamas was about to change its tune, although a new poll showed the vast majority of Palestinians both back Mr Abbas's call for a referendum and intend to vote in favour of a document first drawn up by a cross-party group of senior militants held in Israeli prisons.
Hamas prime minister Ismail Haniya said a further round of talks would be "the only way to resolve our differences."
"We cannot accept that the dialogue has failed. We cannot decide this after just one or two additional meetings as there are many strategic questions to be addressed," he said at the start of the weekly cabinet meeting in Gaza City.
Government spokesman Ghazi Hamad said "the language of threats" would not solve the impasse.
"Dialogue is the best way to reach a compromise. Threats only aggravate the crisis. We must give dialogue another chance," he told a news conference.
The document at the centre of the referendum calls for a national unity government, an end to attacks in Israel and the creation of a Palestinian state alongside Israel on land conquered by the Jewish state in 1967.
Such a blueprint would undercut Hamas's long-time platform of refusing to recognise Israel or disavow the use of violence even within the Jewish state's borders, as well as bounce it into a coalition government with Mr Abbas's Fatah faction, which it trounced in a January election.
In a bid to end growing financial and security crises, Mr Abbas had served Hamas last month with a 10-day deadline, which expired at midnight.
He said there must be a deal on solving the crisis and accepting the idea of a Palestinian state alongside Israel, or that he would put the statehood initiative to a referendum.
Washington welcomed his bold move to resolve the issue once and for all.
"Abbas has demonstrated that he's somebody who wants to work toward a two-state solution," said White House spokesman Tony Snow.
"I think it's important for Palestinians to wrestle with the issue of whether they want to have a two-state solution."
The Hamas government's hardline stance has led it to be boycotted and starved of aid from the European Union as well as the United States, bringing the Palestinian Authority to the brink of financial meltdown.
A power struggle between the Fatah-controlled security services and Hamas has also degenerated into deadly clashes in the Gaza Strip.
Hamas's reticence about a referendum stems in part from the polls, which show voters are likely to give the statehood plan overwhelming backing.
A survey released by the West Bank's Bir Zeit university found that 77 percent of Palestinians intend to vote in favour of the blueprint and that electoral support for Hamas had declined by 13 percent.
The prospect of a deal had long looked bleak amid vicious Fatah-Hamas rivalry, which has left at least 16 people dead since early May.
In the latest outbreak, six Palestinians were wounded when the Gaza City headquarters of the Fatah-dominated preventive security service came under mortar attack in broad daylight.