Amal and George Clooney welcome twins

Amal Clooney on Tuesday gave birth to twins, a boy and a girl, the first children for the international human rights lawyer and her movie star spouse.

"This morning Amal and George welcomed Ella and Alexander Clooney into their lives.

Ella, Alexander and Amal are all healthy, happy and doing fine," George Clooney's publicist Stan Rosenfield said in an email.

He added cheekily, "George is sedated and should recover in a few days."

Amal, 39, and the 56-year-old Oscar-winning star of films like Ocean's Eleven and Three Kings married in Italy in 2014, making them one of the world's biggest celebrity couples.

Rosenfield did not say where the twins were born, but the couple appear to have been spending much of their time recently in England, where they have one of several homes.

The couple adopted a low profile during the pregnancy, keeping the news private for months before it was confirmed in February by the actor's close friend, Matt Damon.

Amal largely continued her work as a human rights lawyer, addressing the United Nations in March and urging the international community to investigate crimes committed by Islamic State in Syria and Iraq.

Nevertheless, celebrity news media speculated for months about the sex of the twins, where they would be born and in which country they will be raised.

On Tuesday, social media lit up with congratulatory messages and "Ella and Alexander" was among the top trending topics on Twitter in the United States.

Many contributors praised the choice of names as a refreshingly normal departure from a trend that has seen celebrity babies given names like Apple, Audio, Bronx, North West and Rocket.

People magazine reported on Tuesday that former US President Barack Obama paid a long, private visit with the Clooneys at their home in the countryside west of London on May 27.

Clooney cancelled a visit to Armenia for a humanitarian event this past weekend, saying in a message to organisers that "if I came there and my wife had twins while I was there, I could never come home."