By Matt Spetalnick and Raymond Colitt
BRASILIA (Reuters) - U.S. President Barack Obama said on Saturday he supported Brazil's "extraordinary" rise on the world stage but stopped short of backing its long-sought bid for a permanent seat on the United Nations Security Council.
At the start of a five-day trip to Latin America, Obama told a briefing in Brazil's capital, Brasilia, that his visit was a "historic" opportunity to strengthen ties between the United States and the region's largest economy in areas such as trade and energy.
Obama is making the trip to ensure a bigger U.S. share in the region's robust economic growth while grappling with deadly crises in Japan and Libya.
In a joint statement, Obama and Brazil's President Dilma Rousseff said they recognized the "need of reforming international institutions to reflect the current political and economic realities."
"President Obama expressed appreciation for Brazil's aspiration to become a permanent member of the Security Council, and acknowledged its assumption of global responsibilities," the statement said.
Rousseff said she was optimistic about U.S.-Brazil relations, which went through a period of tension last year, and saw opportunities for the two nations to cooperate in developing the South American country's vast new oil fields.
In a stern address during which she barely looked at Obama, the former leftist militant also called for an overhaul of the Security Council, saying that international organizations still reflected old power structures.
Brazil believes it deserves a permanent seat on the Security Council in light of its growing clout as an economic and diplomatic power and wants to enlist support from Obama, who backed a permanent seat for India when he visited New Delhi in November.
Anxious to spur job growth back home before the 2012 U.S. presidential election, Obama's visit is part of an effort to reengage with neighbors in a region where the United States faces rising competition from China, which last year became Brazil's biggest trade partner.
Obama went ahead with the tour, which also takes him to Chile and El Salvador, even as world powers were seeking to protect civilians from Libyan leader Muammar Gaddafi and as Japan battled a nuclear crisis.
U.S. officials have said Obama wants to repair diplomatic ties with Brazil under Rousseff, who took office on New Year's Day. Tensions rose under former President Luiz Inacio Lula da Silva over, among other things, Brazil's overtures to Iran.
(Additional reporting by Brian Winter and Todd Benson; writing by Stuart Grudgings and Alister Bull, Editing by Paul Simao)