Viegas did not specify what was being discussed or when an agreement could be reached.
But he stressed that Brazil has "never refused visits and inspections of its uranium-production facilities, and it never will."
The remarks followed a news report Tuesday stating that Brazil denied the UN nuclear watchdog access to a uranium-enrichment facility, claiming it needed to protect industry trade secrets.
The IAEA sought access to the facility in Resende, IAEA director Mohamed ElBaradei said in an interview in Moscow with the daily O Globo, published Tuesday.
ElBaradei told the daily that Brazil should not be an exception to IAEA norms. He said the IAEA needed to see the equipment itself because it was the only way to ensure that no uranium was being enriched beyond that which had been declared.
Brazilian authorities reportedly offered to allow the IAEA to weigh uranium leaving the facility.