"But the problem will start after 2011 - the politicians must find other ways to fill the void after 2011. If I were asked about the withdrawal, I would say to politicians: the US army must stay until the Iraqi army is fully ready in 2020."
Withdrawal 'on target'
Saad al-Mutalibi, an Iraqi government spokesman, told Al Jazeera that Zerbari was probably speaking "academically" and said his comments were "personal and represented his own thoughts".
Al-Mutalibi said Iraq is conducting a "strategic war against terrorism" and suggested it does not yet need a large military.
"The security forces still need more training to become more effective at security functions"
Iraqi prime minister
"We pose no threat to our neighbours, none of our neighbours at present pose any threats", he said. "We resolve all our differences ... through dialogue and peaceful resolution of issues".
Hours after Zerbari's comments, Robert Gibbs, the White House spokesman, told reporters that the US is still "on target" to withdraw troops from Iraq. He said only "dozens" would remain at the US embassy in Baghdad after 2011.
"We're on target by the end of the month to end our combat mission," Gibbs said at a news conference on Wednesday.
Iraqi officials have made contradictory statements about the country's readiness to take over security from US forces, Al Jazeera's Omar al-Saleh reported from Baghdad.
Just two days ago, General Ali Ghaidan, the commander of all Iraqi ground forces, told reporters at a news conference that his troops are "100 per cent ready" to take over, al-Saleh said.
There are currently 64,000 US troops in Iraq, a number that is expected to fall to 50,000 by next month.
The United States is also looking to begin drawing down its financial assistanceto the families of Iraqis killed in US combat operations.
|Prime minister Nouri al-Maliki acknowledged Iraqi troops have not 'ended terrorism' [AFP]
A programme administered by the US Agency for International Development (USaid) in Baghdad has dispersed tens of millions of dollars to thousands of Iraqi families in the years since the US invasion, but funding is decreasing and some members of Congress have called for USaid to find a way for Iraq to take over the project.
"Their message to us is: 'Solve your problems quickly so that we can withdraw quickly'," Hoshyar Zebari, the Iraqi foreign minister, told The Associated Press news agency.
Violence over the weekend left at least 60 people dead across the country, including 43 killed in bomb blasts in the southern city of Basra.
Though violence in Iraq has dipped since it peaked in 2006 and 2007, security consulting firm AKE estimatesan average of 50 Iraqis have died each week in 2010.
Nouri al-Maliki, the prime minister, told the Iraqi newspaper al-Rafidaynon Thursday that while the Iraqi security forces have not "ended terrorism" in the past few years, they have "created conditions for the process of reconstruction".
"The security forces still need more training to become more effective at security functions," he said.
Meanwhile, a senior White House advisor suggested that the US military presence in Iraq after the main pullout in 2011 could be limited to "dozens" or "hundreds" of troops under the embassy's authority.
"We'll be doing in Iraq what we do in many countries around the world with which we have a security relationship that involves selling American equipment or training their forces, that is establishing some connecting tissue," Anthony Blinken, the national security advisor for vice-president Joe Biden, said.
"When I say small, I'm not talking thousands, I'm talking dozens or maybe hundreds, that's typically how much we would see."
The US deployment in Iraq reached its peak in 2007 at 170,000 troops but their presence has gradually diminished over the past 18 months.