The couple celebrated the president's birthday with dinner at award-winning Rasika restaurant near the White House in Washington's West End neighbourhood Thursday. "The President and First Lady are going out to dinner to celebrate his birthday," the White House said.

Leaving the White House earlier, Michelle was spotted wearing a knee-length, backless black dress. The president was dressed in his usual suit.

According to the restaurant's website, Rasika serves modern Indian cuisine, offering "small plates, a modern lounge, and a temperature-controlled wine cellar."

The travelling press pool reported "few people seemed to notice as the motorcade drove down Pennsylvania Ave, stopping at the lights along the way."

The president, who turned 52 on Sunday, spent his birthday weekend celebrating with friends and family at Camp David. Rasika restaurant, owned by Delhi-born Ashok Bajaj's Knightbridge group, is a popular restaurant in Washington. Bajaj owns award-winning restaurants in UK and US.