Obama hailed a "remarkable" transformation in the country also known as Burma, which spent five decades under oppressive military rule. Suu Kyi's party swept historic elections last November, and the visit by the 71-year-old Nobel Peace Prize laureate, deeply respected in Washington, is a crowning occasion in the Obama administration's support for Myanmar's shift to democracy, which the administration views as a major foreign policy achievement.
The U.S. has eased broad economic sanctions since political reforms began five years ago and Obama has visited the country twice. But the U.S. has retained more targeted restrictions on military-owned companies and officials and associates of the former ruling junta. U.S. companies and banks have remained leery of involvement in one of Asia's last untapped markets.
"The United States is now prepared to lift sanctions that we have imposed on Burma for quite some time," Obama said as he sat alongside Suu Kyi in the Oval Office. He said it was "the right thing to do" to ensure Myanmar benefits from its transition. Asked by a reporter when sanctions would be lifted, Obama said "soon."
Suu Kyi concurred it was time to remove all the sanctions that had hurt the economy. She urged Americans to come to the country and "to make profits."
Congressional aides said that Suu Kyi requested the removal of the national emergency with respect to Myanmar — the executive order authorizing sanctions that has been renewed annually by U.S. presidents for two decades.
The Treasury Department said that Obama's decision will be legally effective when he issues a new executive order to terminate the emergency. A U.S. official said that 111 Myanmar individuals and companies will be dropped from a Treasury blacklist and restrictions will be lifted on new investment with military and on the imports of rubies and jade. But penalties intended to block the drug trade and to bar military trade with North Korea would still apply, as would a visa ban barring some former and current members of the military from traveling to the U.S.
The official and aides spoke on condition of anonymity as they were not authorized to discuss the matter publicly.
The U.S. Chamber of Commerce hailed the announcement as "historic." But human rights groups say there are powerful reasons for retaining sanctions. Military abuses continue in ethnic minority regions. Rohingya Muslims remain displaced by sectarian violence and denied citizenship. The military and its associates still have huge stakes in the economy.
"Obama and Suu Kyi just took important tools out of their collective tool kit for dealing with the Burmese military, and threw them into the garbage," said John Sifton, deputy Washington director for Human Rights Watch.
Transparency watchdog Global Witness says Myanmar's jade industry, based in a northern region plagued by civil conflict, is dominated by a military elite, U.S.-sanctioned drug lords and crony companies. It estimates the industry is worth nearly half of the nation's economic output.
Suu Kyi addressed problems in western Rakhine state, where more than 100,000 Rohingyas remain stuck in camps, separated from Buddhists who are the majority in Myanmar. She said everyone entitled to citizenship in Myanmar should get it.
"We are sincere in trying to bring together the different communities," Suu Kyi said.
The White House also notified Congress on Wednesday it would be reinstating in November trade benefits to Myanmar because of its progress on workers' rights. The benefits were suspended in 1989, a year after the bloody crackdown on democracy protesters by the military.
Suu Kyi last visited Washington in 2012 when she was still opposition leader. On that occasion, she was presented with the Congressional Gold Medal, the legislature's highest civilian honor, which she had been awarded in 2008 while under house arrest.
Now she is de facto leader of the country with the title of state counsellor although a junta-era constitution still enshrines the military's role in politics and bars her from the presidency.
White House spokesman Josh Earnest pushed back on the notion the U.S. was undercutting its leverage over Myanmar on human rights and constitutional reforms by lifting sanctions. He said greater U.S. engagement would promote its ability to promote change.
Associated Press writers Kathleen Hennessey and Josh Lederman contributed to this report.