London, June 14 (ANI): Queen Elizabeth II and Michelle Obama have struck a firm friendship since they first met at the G20 summit in London in April, according to sources.

The Queen, in what was suggested to be a sign of close bonding, allegedly let the US First Lady and her daughters to have a rare guided tour of Buckingham Palace during their visit to the capital last week.

Michelle and her girls Malia, and Sasha, purportedly treaded the royal floors of the Monarch's official London residence and its 40 acres of gardens as part of Sasha's birthday treat on their final day of the sightseeing trip, reports The Telegraph.

The trio were later alleged to have been warmly greeted by the Royal at the end of their hour-long tour.

The Queen, 83, and Michelle, 45, have apparently forged a warm friendship after sharing similar interests, such as their love for the countryside, gardening and clothes, reports The Telegraph.

During the Obamas' visit for G20 summit, the pair were even snapped affectionately hugging each other, which was thought to be an unprecedented display of intimacy by the Queen towards a foreign dignitary.

And before bidding goodbyes, the Queen was overheard as saying: "Now we have met, would you please keep in touch?"

The two women have since maintained contact through letters and telephone, according to sources.

Buckingham Palace declined to comment on the Queen's relationship with Michelle or on the latter's alleged royal tour last week. (ANI)