The first Kuwaiti ambassador to Iraq since the Gulf state was invaded by its larger neighbour in 1990 has taken up his post in Baghdad.
Diplomatic ties between the two countries were severed after the invasion, and restored following the ousting of Saddam Hussein in 2003.
Ambassador Ali Mumin joins envoys from Jordan and Syria, who arrived in Baghdad in the past two weeks.
A number of other Arab states have said they will follow suit soon.
The influx of Arab ambassadors follows improvements in security in Baghdad and pressure from the US on its regional allies to support the government.
Mr Mumin appeared at a news conference in Baghdad with Iraqi Foreign Minister Hoshyar Zebari after presenting his credentials.
"The political leaders of the two countries have decided to forget the past and build good relations between them," he said.
The two neighbours, both with massive oil reserves, have yet to settle a number of issues related to the war, in particular compensation to Kuwait estimated to amount to tens of billions of dollars