Vice President Joe Biden sought to smooth political differences among Iraq's fractious political officials on his first full day in the country, as the American military moves ahead with plans to pull troops out of the country.

BAGHDAD — Vice President Joe Biden sought to smooth political differences among Iraq's fractious political officials on his first full day in the country, as the American military moves ahead with plans to pull troops out of the country.

Biden's arrival was marred by a rocket attack against the Green Zone on Tuesday evening that killed two Iraqi civilians. The attacks took place after Biden had retired for the night following meetings with American officials on the first day of his visit to Iraq.

The U.S. military said three suspects detained near the site where the four rockets were fired at the fortified zone in downtown Baghdad were later released.

They were questioned by Iraqi security forces who found insufficient evidence to detain them, the military said. The 107 mm rockets were fired from the outskirts of the massive Shiite district of Sadr City.

Biden met a broad spectrum of Iraqi officials in Baghdad, trying to help smooth political differences as the American military moves ahead with plans to pull troops out of the country.

He held talks first with parliament speaker Ayad al-Sammaraie, a senior member of the Iraqi Islamic Party, the country's largest Sunni political party.

The two sides discussed developments in the country's national reconciliation efforts with former Saddam loyalists and other Iraqi internal issues, al-Sammaraie's spokesman Omar al-Mashhadani told AP. He gave no further details.

He also met Shiite Vice President Adel Abdul-Mahdi and said as he sat with him that "you can't get rid of me."

"I keep coming back, coming back," he said, in a joking reference to his frequent visits to Iraq. The current visit is his third this year.

The American vice president was also meeting with Prime Minister Nouri al-Maliki, a Shiite, and Sunni leaders including Vice President Tariq al-Hashemi ahead of meetings with Kurdish officials on Thursday.

Over his three-day visit, Biden's main focus was expected to be plans for January elections and the ongoing violence in Iraq's north. As the number of bombings and other attacks declines elsewhere in Iraq, the north remains a battleground between Sunni Arab extremists and Iraqi and U.S. forces. Kurdish-Arab tension there also frequently flares into violence.

"The whole purpose is to see how we can be helpful, if we can, in helping them resolve the outstanding political issues they have to resolve internally, so that when the (security agreement) is fully implemented we leave a stable Iraq," he told reporters late Tuesday after meeting with Gen. Ray Odierno, the top U.S. commander in Iraq, and U.S. Ambassador Christopher Hill.

The U.S.-Iraqi security agreement calls for the withdrawal of American combat forces by the end of August 2010 and of all U.S. troops by the end of the following year.

Biden said that Odierno was optimistic that the readiness of Iraqi forces would allow the U.S. military to withdraw all combat forces next year according to plan, and then proceed with pulling out the remaining 50,000 troops by the end of the following year.

There are now about 130,000 U.S. troops in Iraq.

Biden last visited Iraq on July 4 to spend U.S. Independence Day with the troops. During that trip he also met with his son, Beau, who is an Army captain serving in Iraq.