The United States pledged to assist Sri Lanka's new government in creating a more open and democratic society.
In a speech laying out President Barack Obama's updated national security strategy, U.S. National Security Adviser Susan Rice included Sri Lanka alongside Myanmar and Tunisia as a country "in transition."
Earlier, State Department spokeswoman Marie Harf said the United States had commended steps by President Maithripala Sirisena to address post-war reconciliation and long-standing issues such as governance and accountability.
On Thursday, Nisha Biswal, the U.S. State Department's senior official for South Asia, who visited Sri Lanka last week, told reporters Sri Lanka still faced "big challenges" dealing with issues such as reconciliation.
The United States is keen to bolster ties with countries throughout Asia as part of its effort to counterbalance an increasingly powerful and assertive China, which has sought strategic influence in Sri Lanka.
Sri Lanka's new Foreign Minister Mangala Samaraweera is expected to visit Washington next week.