The US has said it will ease restrictions on investment to Burma and quickly appoint an ambassador as it seeks to boost reformers who allowed landmark elections.
The moves are the latest gestures under a three-year diplomatic drive on Burma, which is also known as Myanmar.
The US said it would step up aid and allow select officials to visit, but it stopped short of easing the bulk of two decades worth of sanctions.
Secretary of State Hillary Clinton hailed the "leadership and courage" of President Thein Sein after the opposition swept Sunday's by-elections.
The by-elections saw Nobel prize winner Aung San Suu Kyi win her first seat in parliament.
"The United States will stand with the reformers and the democrats both inside the government and in the larger civil society as they work together for that more hopeful future that is the right of every single person," Mrs Clinton said.
Mrs Clinton announced "the beginning of the process" of a "targeted easing of our ban on the export of US financial services and investment" to the country.
She said the step on investment was "part of a broader effort to help accelerate economic modernisation and political reform".
But she warned: "Sanctions and prohibitions will stay in place on individuals and institutions that remain on the wrong side of these historic reform efforts."
Mrs Clinton previously announced that the US would restore full diplomatic relations with Burma for the first time in two decades.
She said the administration would complete formalities "in the coming days" and then formally nominate an ambassador to the Senate for confirmation.
