WASHINGTON, April 17 (Xinhua) -- Former U.S. First Lady Barbara Bush died Tuesday at the age of 92, days after she decided to give up treatment for her illnesses.

A spokesman of the Bush family made the announcement on twitter Tuesday evening, prompting a wave of condolence messages.

Barbara Bush served as the first lady during her husband George Bush's presidency between 1989 and 1993. She is also the mother of former President George W. Bush, who served between 2001 and 2009.

In her capacity as the first lady, Barbara Bush was known to have advanced the cause of universal literacy and founded the Barbara Bush Foundation for Family Literacy.

Barbara also accompanied George Bush to China to head the U.S. liaison office there in 1974.

"Mom kept us on our toes and kept us laughing until the end. I'm a lucky man that Barbara Bush was my mother. Our family will miss her dearly, and we thank you all for your prayers and good wishes," George W. Bush said in a statement.

"President Donald J. Trump and First Lady Melania Trump join the Nation in celebrating the life of Barbara Bush," a White House statement said, adding that she "will be long remembered for her strong devotion to country and family."

"Throughout her life, Barbara Bush showed us all the importance of charity, literacy, and love of country. Our thoughts are with the entire Bush family as they mourn her passing. Rest In Peace," said Apple CEO Tim Cook.