The original name of the union was changed to the current one, the Union of South American Nations, in April 2007.

It announces the foundation of the Union of South American Nations.

In 2008, the city was designated as the headquarters of the Union of South American Nations.

In 2008, the country joined the Union of South American Nations as a founding member.

Eight heads of state and four foreign ministers of the Union of South American Nations attended the summit.

The Union of South American Nations is expected to merge both trade blocs.

There are currently 12 member states of the Union of South American Nations.

Argentina is also a full member of the Union of South American Nations.

Both countries are members of the Union of South American Nations.

The name was finally changed on 16 April 2007 to Union of South American Nations.