Donald Rumsfeld, the former US defence secretary and main architect of the Iraq and Afghanistan war, died on Wednesday aged 88.

Mr Rumsfeld served from 2001-2006 until President George W. Bush replaced him as the US found itself bogged down after more than three years of fighting.

He was surrounded by family in his beloved Taos, New Mexico, the family said in a statement released on Wednesday. It is not clear how he died.

"History may remember him for his extraordinary accomplishments over six decades of public service, but for those who knew him best… we will remember his unwavering love for his wife Joyce, his family and friends, and the integrity he brought to a life dedicated to the country," the family said.

A statement from the family of Donald Rumsfeld: pic.twitter.com/AlKYxVvqgF

— Donald Rumsfeld (@RumsfeldOffice) June 30, 2021

He had a long public career spanning several decades in Congress, the Pentagon and in the White House as chief of staff, but is most known for second term as defence secretary during the most tumultuous period of the Iraq and Afghanistan wars.

Mr Rumsfeld oversaw the Pentagon’s response to the 9/11 terror attacks and its initial attack on al-Qaeda bases in Afghanistan, leading the charge on America’s so-called “war on terror”.

Two years later, US forces invaded Iraq to prevent Saddam Hussein from launching attacks with weapons of mass destruction. None were found, despite claims from Mr Rumsfeld.

"There are known unknowns," he said in response to a question at a Department of Defense news briefing in early 2002, about the lack of evidence, a phrase that was oft-quoted over the years.

Read more: Donald Rumsfeld, Cold War warrior and defence chief during Iraq war who was indelibly associated with his ‘known unknowns’ – obituary

Donald Rumsfeld gestures during a press conference at the Pentagon in 2003

The mismanaged American occupation led to a guerrilla war and sectarian violence.

By 2006, the wars and Mr Rumsfeld’s handling of them had become a political liability for Mr Bush. He fired Rumsfeld shortly after the midterm elections and replaced him with Robert Gates.

There were a series of high-profile controversies during his tenure, including the abuse of Iraqi prisoners at the Abu Ghraib prison, as well as the detention without trial of prisoners at the military prison at Guantanamo Bay, Cuba.

Mr Rumsfeld personally authorised harsh interrogation techniques for detainees.

He is the only person to serve twice as Pentagon chief. The first time, in 1975-77, he was the youngest ever. The next time, in 2001-06, he was the oldest.

Rumsfeld was sacked by Bush in 2006

Credit: GETTY IMAGES

Mr Bush paid his respects, saying in a statement: "As Commander in Chief, I especially appreciated how Don took his job personally and always looked out for the interests of our servicemen and women. He was a faithful steward of our armed forces, and the United States of America is safer and better off for his service."

After retiring in 2008 he headed the Rumsfeld Foundation to promote public service and to work with charities that provide services and support for military families and wounded veterans.

Rumsfeld is survived by his wife, Joyce, three children and seven grandchildren.