Washington: Rahul ‘Richard’ Verma, a key aide of US Secretary of State Hillary Clinton, has quit from the Obama administration to return to the private sector.

He is the second high-ranking Indian-American official to quit Obama’s team.

As assistant secretary of state for legislative affairs, Verma was Clinton's principal advisor on Congressional affairs for nearly two-and-a-half years and played a lead role in a wide range of critical international initiatives and legislative actions.

These included securing ratification of the New Strategic Arms Reduction Talks treaty with Russia negotiating comprehensive sanctions against Iran and obtaining passage of the United Kingdom and Australian defence cooperation treaties.

At a farewell reception for Verma at the State Department, Clinton said, “Richard has just been our superb point person on the Hill.

He hasn't just been an absolutely, exemplary deal-closer and problem-solver, he has been a counsellor and friend in the truest sense of the word.”

In a personal letter of appreciation, President Barack Obama too extended 'my sincere thanks for your valuable service to my administration’.

Verma, who at the time of his confirmation was the highest-ranking Indian American to serve in the State Department, will return to the international law firm of Steptoe &Johnson LLP as a partner in its Washington office.

He will practice in the firm's international, national and homeland security, and government affairs and public policy groups.

Last year, Neera Tanden quit the administration after serving for over a year as senior advisor to Secretary of Health and Human Services Kathleen Sebelius and after playing a key role in the formulation of Obama's health-care reform proposals.