ABC News' Cecilia Vega reports:

President Obama said today he has no doubt Iraq will succeed as an independent, post-war nation, but that history will judge America's decision to invade the country nearly nine years ago.

Obama and Iraqi Prime Minister Nouri al-Maliki stood side-by-side after a morning meeting at the White House where they discussed the final days of U.S. troop presence in Iraq and future relations between the two countries.

"As we end this war and as Iraq faces its future, the Iraqi people must know that you will not stand alone," Obama told Maliki during a joint news conference. "You have a strong and enduring partner in the United States of America."

About 6,000 U.S. troops remain in advance of the Dec. 31 withdraw deadline, down from 170,000 at the peak in 2007.

Obama said the United States will still maintain a "strong diplomatic presence" inside Iraq, including about 16,000 people working in the embassy in Baghdad, but all troops will leave the country and all military bases will close.

And while Obama said America does not want "to create big footprints" inside the country, he also warned other nations not to interfere with a sovereign Iraq.

"We discussed how the United States could help Iraq train and equip its forces, not by stationing American troops there or with U.S. bases in Iraq - those days are over - but rather the kind of training and assistance we offer to other countries," Obama said.

The two countries will continue to have strong military ties and today National Security Council spokesman Tommy Vietor said the administration notified Congress of its intent to sell 18 more F-16 fighter jets to Iraq.

Maliki said goals set between Iraq and the United States were achieved.

"Iraq had a political process established, a democratic process, and adoption of the principles of elections," he said.

After the joint news conference, Obama and Maliki visited Arlinton National Cemetery, where some of the nearly 4,500 Americans killed during the war are buried.