Iraq's parliament endorsed the last-minute changes to the constitution on Wednesday evening.
The parliamentary endorsement and the president's upbeat message came as fighters continued deadly attacks around Iraq, with one bomber exploding himself at an army recruitment centre in the northwestern town of Tal Afar, killing 30 and wounding 35.
In Baghdad, Aljazeera has learned, a federal minister escaped an assassination attempt when a convoy of government cars preparing to pick him up at his office was hit by a car bomber. Five of his bodyguards and five Iraqi bystanders were wounded in the attempt.
Those and other attacks by fighters on Wednesday raised Iraq's toll over the last 17 days to 425, with the number of fatalities based on police reports.
Nonetheless, the Iraqi government has urged people to ignore attacks and vote "yes" for the document aimed at advancing the country's democratic reforms.
"I have good news for the Iraqi people on this historic day. An agreement has been reached on amendments to the draft constitution," Talabani said during a nationally televised news conference.
"There is no excuse for Arab Sunnis to boycott the vote now that we have responded to all their demands and suggestions."
Talabani was followed at the microphone by several other Iraqi politicians who also praised the consensus reached on Tuesday night by Sunni, Shia and Kurdish power brokers on the charter before Saturday's referendum.
A bid on the life of a minister left
bodyguards and civilians injured
The draft constitution has been printed by the United Nations and millions of copies are being distributed to the public for the vote, so the additions cannot be included.
The changes were made on Tuesday night by power brokers from Iraq's Shia lawmakers and Sunni and Kurdish representatives in an attempt to address concerns among Sunni Muslim Arabs that have prompted many of them to say they will vote no.
The deal the negotiators reached approved the mechanism by which the constitution may be amended if it is approved in Saturday's nationwide vote.
But as politicians discussed the constitution, Tal Afar was reeling from its second major bombing in two days.
On Tuesday, a car bomber ploughed his explosives-packed vehicle into a crowded outdoor market in Tal Afar, killing 30 civilians and wounding 45. Al-Qaida in Iraq later claimed responsibility for the attack.
In August, US and Iraqi forces conducted a major offensive in Tal Afar, 150km east of the Syrian border, claiming to have killed 200 fighters and driving many others out of the small town.
"There is no excuse for Arab Sunnis to boycott the vote now that we have responded to all their demands and suggestions"
Also on Wednesday, three car bombers and two roadside bombs killed one Iraqi and wounded 28 in several attacks in Baghdad and the northwestern city of Baquba.
The Baghdad strikes included a car bomb that hit a convoy of government cars preparing to pick up Saad Naif Al-Hardan, Iraq's minister for provincial affairs, at his office.
The attack seriously wounded five of its bodyguards and five civilian bystanders, police said.
Elsewhere, an explosion set by fighters also shut down a pipeline that transports oil from the northern oil centre of Kirkuk to refineries in Beiji, from where it is also pumped via the country's export pipeline to the port of Ceyhan, in Turkey, an official said.
The Kirkuk-Beiji pipeline is critical to Iraq's oil export operations, but that line is only intermittently open because of incessant sabotage.