A deputy foreign minister will lead the Iranian delegation to the conference of Iraq's neighbors and the Big Five of the U.N. Security Council. The meeting will be the first public encounter between U.S. and Iranian envoys since late 2004.
"We hope the conference will result in sending a clear message that the countries of the region are standing alongside the government and nation of Iraq," Mottaki told a news conference.
Mottaki said the chief Iranian delegate would be the deputy foreign minister for legal and international affairs, Abbas Araghchi.
On Monday, Mottaki said his government was finalizing its decision on whether to attend the conference. He indicated that Iran was in favor of participating but it did have reservations.
"With the aim of helping the government and people of Iraq, an Iranian delegation will attend the Baghdad conference," Mottaki said Wednesday in the first unequivocal commitment to the event.
The Iraqi government invited countries to the conference last week. The United States quickly said it would attend, making a diplomatic shift after months of refusing to talk to Iran about calming the conflict in Iraq.
Mottaki said Monday that his government had "some concerns" about the conference. He did not spell these out, but it is thought Iran fears that both the U.S. and Iraqi delegations might accuse Iran of supporting Shiite armed groups in Iraq.
The United States has recently hardened its line on Iran, both diplomatically and militarily.
President George W. Bush has stepped up accusations that Iran is backing Shiite militants in Iraq. The U.S. military has detained a number of Iranians in Iraq and strengthened its naval presence in the Gulf.
Washington is also leading a push for stronger sanctions against Iran over its defiance of U.N. Security Council demands that it stop enriching uranium, a process that provides material for nuclear reactors or atomic warheads.
The last time U.S. and Iranian envoys met in public was in late 2004 at a meeting of 20 nations in the Egyptian resort of Sharm el-Sheik to discuss Iraq's future. Then-Secretary of State Colin Powell and his Iranian counterpart, Kamal Kharrazi, did not hold formal talks, but Egypt sat the two officials next to one another at a dinner. Powell said the two mostly had "polite dinner conversation."