"We have to be very careful that we're not lured by the mirage ofsuccess," Suu Kyi said after meeting Obama at her home in Yangon.
Hundreds of her supporters gathered outside Suu Kyi's compound to greet the first sitting US president to visit the country, many of them chanting, "Obama, freedom."
Obama has been criticised by human rights groups for using his trip to endorse the government of reform-minded President Thein Sein, whom he met earlier Monday.
"Our goal is to sustain the momentum for democratization," Obama said, after earlier acknowledging that the country had a "long journey" to full democracy.