"If the provisional government asks us to leave we will leave," he said, referring to a post 30 June administration after the handover of sovereignty.
"I don't think that will happen but obviously we don't stay in countries where we're not welcome," he said at a working lunch in Baghdad with Iraqi officials from Diyala province.
"The CPA (Coalition Provisional Authority) dissolves on 30 June. Does that mean that the United States is going away? Absolutely not," he said.
The make-up of the provisional government is still under discussion.
The three main tasks of the 30-strong transitional government over its seven-month lifespan will be running the country, preparing for elections and dealing with the security issue.
But critics have questioned how much sovereignty the new Iraq will have, noting that the United States will still maintain an autonomous military presence in the country.
UN special envoy, al- Akhdar al-Ibrahimi, is currently in Iraq consulting on the make-up of a post-June 30 administration.
Bremer told the officials, including the governor of Diyala, Abd Allah Hasan Rashid, he was working with the United Nations, but it was too early to say who would be on the provisional government.
He said he believed it would be a combination of "people chosen for their technical capabilities ... (and) people who are technically capable".
Key political leaders
The current president of Iraq's US-appointed interim Governing Council said on Wednesday key political players in the country should remain in government after 30 June.
Abd al-Zahra Uthman Muhammad, also known as Izz al-Din Salim, said the transitional government should include "experienced people with concrete social and political connections".
"Our troops will stay in Iraq ... Just because there's a transition, and just because we're going to move from this election to that election does not mean America will leave Iraq. We are not going to leave this job undone"
US Undersecretary of State for Political Affairs
Members of the governing council have been concerned about reports suggesting that al-Ibrahimi intended to invite technocrats to form the interim government, leaving council members to contest the January elections.
Marc Grossman, undersecretary of state for political affairs, told a hearing of the House International Relations Committee on Iraqi sovereignty on Thursday panel that if asked, US forces would indeed be compelled to pull out - although he quickly added: "I do not believe they will ask us to."
"Our troops will stay in Iraq," he said. "Just because there's a transition, and just because we're going to move from this election to that election does not mean America will leave Iraq. We are not going to leave this job undone."
An opinion poll conducted for the CPA and quoted by Thursday's Washington Post showed that 80% of Iraqis mistrust the coalition authority and 82% disapprove of US and allied occupation forces in their country.