Joanne Drake, a spokesperson for the Reagan Foundation, confirmed the death of the former first lady Nancy Reagan.

"Nancy Davis Reagan, former first lady of the United States, died this morning at her home in Los Angeles at the age of 94. The cause of death was congestive heart failure," read a press statement from the foundation.

Michael Reagan, the adopted child of Ronald Reagan and his first wife Jane Wyman, said he was saddened by the news, first reported by celebrity news site TMZ.

"I am saddened by the passing of the step mother Nancy Reagan. She is once again with the man she loved. God bless," said Michael in a tweet.

The former first lady was widely known for her widely-publicized "Just Say No" anti-drug campaign while her husband served in office.

During her stay at the White House from 1981 to 1989, she went from being considered a pre-feminist throwback to a revered "dragon lady" who heavily influenced Reagan's administration.

'A final goodbye to the days of Reagan'

Former Massachusetts Governor Mitt Romney said Nancy's "charm, grace and passion for America" shined throughout her life.

"With the passing of Nancy Reagan, we say a final goodbye to the days of Ronald Reagan. With charm, grace and a passion for America, this couple reminded us of the greatness and the endurance of the American experiment," Romney said in a statement posted to his Facebook account.

"Some underestimate the influence of a first lady, but from Martha and Abigail through Nancy and beyond, these women have shaped policy, strengthened resolve, and drawn on our better angels. God and Ronnie have finally welcomed a choice soul home," the former presidential candidate noted.

ls/jlw (Reuters, AFP, AP, dpa)