Joe Biden told Nouri Maliki the US did not want to interfere in Iraqi politics
US Vice-President Joe Biden has been holding talks in Iraq to try to defuse a political crisis over candidates for the general elections in March.
More than 500 have been banned so far, many on suspicion of loyalty to Saddam Hussein's dissolved Baath Party.
The dispute has caused bitter recriminations among Iraqi politicians.
Many Sunnis are outraged, saying their community is being marginalised, while many Shias oppose both rehabilitating Baathists and US interference.
Mr Biden began by meeting the UN secretary general's special representative for Iraq, Ad Melkert, for a working breakfast, before holding talks with Prime Minister Nouri Maliki.
Government spokesman Ali Dabbagh said during his meeting with Mr Maliki, Mr Biden had stressed that the US did not want to interfere in the dispute over election rules.
"[Mr Biden] clearly said that this is an Iraqi issue and he is not willing to interfere with the legal and constitutional process," Mr Dabbagh said.
Foreign Minister Hoshyar Zebari told AFP news agency the pair's talks had focused on general diplomatic relations between the two countries.
Mr Biden was also due to meet President Jalal Talabani and other key political figures.
The BBC's Jim Muir in Baghdad says both the US and UN are increasingly worried that the March elections could become discredited.
Mr Maliki, who belongs to the Shia community, has generally been supportive of the disqualifications.
A protester with a ripped poll poster for banned candidate Dhafir al-Ani
However, Mr Talabani, who is a Kurd, has questioned the legality of the commission which issued the disqualifications, referring it to the supreme court for a ruling.
Our correspondent says Mr Biden will have to tread carefully as, particularly in Shia circles, political interference and pressure from the Americans is a deeply sensitive issue.
He says Mr Biden may not achieve an immediately visible success but the Americans will be eager for the elections to foster national reconciliation so the withdrawal of troops can be achieved against a stable background.
Tony Blinken, Mr Biden's national security adviser, said the vice-president would not be heavy handed.
"I don't think it's the place of the United States or any other outside country to resolve these kinds of problems for Iraqis," he said.
"We want to be as helpful as the Iraqis want us to be in helping them resolve these problems. Because, ultimately, [those problems] are what stands between Iraq and a successful, stable future."
Mr Blinken said the timetable for withdrawing all US combat troops by August, with a full military pullout in 2011, remained on track.
The election blacklist targets former members of the Baath party, the Fedayeen militia and Mukhabarat intelligence agency.
Ahead of the vice-president's visit, Mr Talabani suggested Mr Biden had proposed "that the disqualifications be deferred until after the election and that those candidates who have been barred condemn and disavow the Baath party and undertake to act through democratic means".
Although violence has lessened in Iraq over the past two years, security remains fragile.
Both Iraq and its Western backers see the March election as a crucial test of whether peace can be made sustainable.