Tariq al-Hashemi, the Iraqi vice-president, told Al Jazeera on Friday: "President Bush is very worried and annoyed [about the sectarian violence].
"He made it clear to me saying, 'we cannot remain silent towards the situation, we cannot accept that Iraqis kill each other. Decisive measures are needed to stop the killings'."
Al-Hashemi held meetings with Bush in Washington this week.
The conference will bring together Kurdish, Shia Muslim and Sunni Arab politicians from the ruling coalition in Baghdad and figures from Saddam Hussein's former Baath party who have been living abroad since the US-led invasion in 2003.
They are expected to discuss issues ranging from the presence of US and other foreign troops to sectarian militias.
Ali Dabagh, the government spokesman, said: "Around 200 figures have been invited to this conference."
Among issues to be discussed in a series of workshops on Saturday will be a process known as debaathification, which bans former members of Saddam's party from any role in public office and the military, a major Sunni complaint.
"The main goal is to reduce the circle of those included in debaathification to include ... only those who committed crimes against Iraqis," said Abbas Bayati, from the powerful Shia Alliance.
Iraq has held conferences before designed to bring about reconciliation but they failed to stop sectarian bloodletting or bring into the fold some Sunni groups who have boycotted the US-backed political process.
Rice in opposition
Meanwhile, Condoleezza Rice, the US secretary of state, has rejected a bipartisan panel's proposal that the Bush administration engage Syria and Iran in efforts to stabilise Iraq.
Rice told the Washington Post newspaper in an interview on Friday that the "compensation" required for any such deal might be too high.
Rice said she did not want to trade away Lebanese sovereignty to Syria or allow Iran to obtain a nuclear weapon as a price for peace in Iraq, the Post reported.
She also argued that neither Syria nor Iran should need incentives to promote stability in Iraq, the Post reported.
"If they have an interest in a stable Iraq, they will do it anyway," Rice said.
In a related development, Jawad al-Boulani, the Iraqi interior minister, arrived in Syria on Friday for talks on strengthening security along the two countries' border.
Al-Boulani said on arrival that he and his Syrian counterpart would sign agreements to set up joint security patrols along the long desert border.
Both the US and Iraq have accused Syria of failing to take sufficient steps to stop armed groups from infiltrating into Iraq to fight the US-led forces and Iraqi government troops.
Syria has repeatedly denied the charge, complaining that it cannot completely seal its border with Iraq.