An official at the U.S. embassy in Brasilia declined to confirm or deny the report.

Ties between the Western Hemisphere's two most populous countries had suffered during most of the past year. Rousseff's predecessor, Luiz Inacio Lula da Silva, angered the United States by seeking close ties with the Iranian government and attempting to mediate a solution in the international standoff over Iran's nuclear program.

Yet there have been signs of a rapid improvement in relations since Rousseff took office on January 1.

Rousseff is a former top aide to Lula and has retained many of his officials in her government, but she has quickly distanced herself from his Iran policy and taken a more critical line on human rights abuses in Iran and elsewhere.

Her government will also reevaluate bids for a multibillion dollar contract to build new jets for Brazil's Air Force. The bidders include U.S.-based Boeing, and Rousseff's decision to start over in the tender process could be a sign she is seeking a closer strategic relationship with the United States.

Rousseff advisers have told Reuters they see the United States as an important partner at a time of global economic uncertainty, especially as tensions grow between Brazil and China over Beijing's trade practices.

**Reporting by Brian Winter; Editing by Vicki Allen