U.S. forces held a formal ceremony to lower the flag in Iraq on Thursday, ahead of their withdrawal from the country nearly nine years after the controversial invasion to topple Saddam Hussein.

The ceremony marking the closure of the U.S. military's headquarters near Baghdad comes after U.S. President Barack Obama hailed the "extraordinary achievement" of the war in a speech to welcome home some of the troops.

A U.S. drone captured by Iran is now the "property" of the Islamic republic, Defense Minister Ahmad Vahidi said Tuesday, after a request by U.S. President Barack Obama for its return.

"The American espionage drone is now Iran's property, and our country will decide what steps to take regarding it," Vahidi was quoted as saying by the ISNA news agency.

President Barack Obama on Monday acknowledged a U.S. drone was in Iranian hands for the first time and said the United States has asked Tehran to return the sophisticated spycraft.

"We've asked for it back. We'll see how the Iranians respond," Obama said at a news conference with Iraqi Prime Minister Nouri al-Maliki.

U.S. President Barack Obama said Monday that "history will judge" the decision by his predecessor president George W. Bush to invade Iraq in 2003.

As an Illinois state senator, Obama had slammed the planned invasion as "a dumb war."

Gunmen attacked NATO oil tankers stranded in southwest Pakistan for the second time in days as Islamabad warned it could enforce its blockade of the U.S. lifeline into Afghanistan for weeks.

The attackers shot dead a driver and destroyed seven tankers in a blaze of fire late Sunday, the second attack in four days in Pakistan's volatile region of Baluchistan, rife with separatist and Taliban insurgency.

President Barack Obama meets Iraqi Prime Minister Nouri al-Maliki Monday, marking America's exit from a war launched in an aerial "shock and awe" assault that went on to deeply wound both nations.

Obama will hold talks with Maliki at the White House, have a press conference and join his visitor at nearby Arlington National Cemetery where many of the nearly 4,500 U.S. war dead lie buried following the 2003 U.S. invasion.

Prime Minister Nuri al-Maliki headed to Washington on Sunday, for the first time as the leader of a country virtually empty of foreign troops as the U.S. withdrawal from Iraq nears its final days.

Maliki is to hold wide-ranging talks with U.S. President Barack Obama during his two-day visit, which comes less than a month before the complete withdrawal of U.S. troops from Iraq and more than eight years after the launch of the U.S.-led invasion that ousted Saddam Hussein.

Republican White House hopeful Newt Gingrich said in an interview out Friday that the Palestinians are an "invented" people and mocked President Barack Obama's effort to be a fair broker of Middle East peace.

"If I'm even-handed between a civilian democracy that obeys the rule of law and a group of terrorists that are firing missiles every day, that's not even-handed, that's favoring the terrorists," said Gingrich.

Republican presidential hopeful Newt Gingrich said Wednesday that Pakistan's nuclear arsenal was at risk of being seized by "extremists" who had probably infiltrated Islamabad's military.

"My guess is that they have well over 100 nuclear weapons and that the Pakistani military is so penetrated by extremist elements you have no idea if one morning, they are going to lose three or four of them. I mean just have them stolen," Gingrich told CNN's Situation Room program.

The United States opened a virtual online embassy Tuesday to reach out to Iranians despite the absence of official ties, vowing to break through the Islamic regime's "electronic curtain."

Iranian authorities have already voiced anger over the virtual embassy, accusing the United States of seeking to interfere in the country after Secretary of State Hillary Clinton announced plans for the project in October.