Flora MacDonald, a veteran Progressive Conservative politician who became a passionate volunteer in retirement, has died at age 89.

MacDonald's executive assistant, Margit Herrman, confirmed to the Canadian Press that the long-time MP died in Ottawa Sunday morning. The cause of death was not immediately available.

Born in North Sydney, N.S., in 1926, MacDonald served as a Progressive Conservative MP for Ontario's Kingston and the Islands riding for 16 years, from 1972 until 1988.

In 1976, MacDonald ran for party leadership, but lost to Joe Clark.

When Clark became Prime Minister in June 1979, MacDonald was named Canada's first female Secretary of State for External Affairs, the position that would later be renamed Minister of Foreign Affairs. She held the role from June 1979 until March 1980, steering the department through the Iranian hostage crisis.

MacDonald also served as the Minister of Employment and Immigration from September 1984 until June 1986, and as the Minister of Communications from June 1986 until December 1988.

She was elected a total of five times, before being defeated by Liberal Peter Milliken in 1988.

After retiring from politics, MacDonald became known for her charity work, volunteering with groups such as Oxfam and Doctors Without Borders.





In 1992 she appointed to the Order of Canada as an officer. Six years later, in 1998, she was promoted to become a companion in the order. The prestigious award recognized MacDonald as a "distinguished former Parliamentarian" who "worked to improve the human condition in Canada and around the world."

On Sunday, a number of prominent Canadian politicians mourned her death and celebrated her accomplishments with messages on Twitter.

I mourn the passing of Flora MacDonald, whose compassion, leadership & example changed lives across our country & around the world #cdnpoli — Rt. Hon. Joe Clark (@RtHonJoeClark) July 26, 2015

Condolences to the family of Flora Macdonald, who served her country at home and abroad. — Stephen Harper (@pmharper) July 26, 2015

Flora MacDonald will be dearly missed. Her leadership blazed a trail in Canada & her humanitarian work improved lives around the world. —TM — Tom Mulcair (@ThomasMulcair) July 26, 2015

Deeply saddened by the passing of Flora MacDonald, a great Canadian whose leadership and compassion will be sorely missed. — Justin Trudeau, MP (@JustinTrudeau) July 26, 2015

Sad to learn of the passing of Flora Macdonald. I recall campaigning with her in Kingston as a Queen's student in '88. — John Baird (@Baird) July 26, 2015

Rest in Peace Hon. Flora MacDonald. Who had a storied political career breaking ground and building a better Canada. — Peter MacKay (@MinPeterMacKay) July 26, 2015

Growing up I knew that Flora MacDonald was a Cabinet Minister originally from Cape Breton. What I understand now is how impt that was. 1/2 — Lisa Raitt (@lraitt) July 26, 2015

Min. MacDonald demonstrated that any career was possible - even for a girl from Whitney Pier. She cleared our path and I am grateful. 2/2 — Lisa Raitt (@lraitt) July 26, 2015

Flora MacDonald was a fine politician and a proud Canadian. She was a stateswoman and will be fondly remembered by all. — Kathleen Wynne (@Kathleen_Wynne) July 26, 2015

With files from the Canadian Press