New Delhi: Days before India and the US hold their second strategic dialogue, the government on Saturday formally announced the appointment of Foreign Secretary Nirupama Rao as its next ambassador to the United States.

Vishnu Prakash, the spokesperson of the external affairs ministry, tweeted Rao's appointment as India's next envoy to Washington on the social networking site.  

Minutes later, the external affairs ministry formally announced her appointment, saying she is expected to take up her assignment shortly.   

Rao's appointment was cleared by the government a few weeks ago. Her tenure as foreign secretary ends on July 31.  Rao will succeed Meera Shankar to become India's second woman ambassador to the US. 

Rao, a former ambassador to China and Sri Lanka, was appointed India’s foreign secretary on August 1, 2009, becoming the second Indian woman to head the Indian Foreign Service after Chokila Iyer.