Secretary of State John Kerry visited Brasilia, Brazil on Tuesday. His focus was to smooth over relations with the United States’ biggest trading partner and the world’s seventh largest economy, and begin preparations for Brazilian President Dilma Rousseff’s visit in October.

Rousseff’s visit is the only official state visit scheduled to occur in Washington, D.C. this year, and is the first by a Brazilian leader since 1995. However, the warming relations between the two countries are now threatened by allegations that the United States intelligence services spied on Brazilians. The Brazilian newspaper O Globo reported last month that the NSA gathered Brazilian telecommunications data, citing documents leaked by former intelligence contractor Edward Snowden.

Secretary Kerry has downplayed the significance of the reports, but is likely to face critical questioning in Brasilia.

“This is really a test of his diplomatic skills,” says Diana Negroponte, nonresident fellow at the Brooking Institution. “He has no money in the bank; he has no aid project; he cannot go and promise any new investments.”

The U.S. does have economic  interests in Brazil, however, as the two countries do over $100 billion of trade each year. A $4 billion deal is currently in the works for 36 jets.

“Brazil needs to modernize its fleet,” says Paulo Sotero, director of the Brazil Institute at the Wilson Center in Washington D.C. “There is a proposal that Brazil buys the F-18 fighter from Boeing.”

Some Brazilian officials are calling this proposal into question after the NSA revelations.

Clearly, Secretary Kerry’s visit is not just about promoting trade, but also about rebuilding trust.