Tony Blair has led tributes to the former UN secretary general Kofi Annan, describing him as a “true statesman”.
Mr Annan died at the age of 80 follwing a short illness, his foundation announced on Saturday.
During his time as secretary general, he clashed with Mr Blair over the 2003 invasion of Iraq by US and British forces, which he denounced as illegal.
However the former prime minister – whose time in No 10 coincided closely with Mr Annan’s time in office – said their differences had not prevented them remaining good friends.
“I’m shocked and distressed to hear the news about Kofi. He was a good friend whom I saw only weeks ago,” Mr Blair said in a statement.
Theresa May said that she was sad to learn of Mr Annan’s death and that her thoughts were with his family.
“A great leader and reformer of the UN, he made a huge contribution to making the world he has left a better place than the one he was born into,” she said.
Former prime minister Gordon Brown, who is currently the UN special envoy for global education, said Mr Annan had fought throughout his life against poverty and injustice.
“Kofi Annan was a leader of leaders, a wonderful humanitarian and the most compassionate and caring of individuals.
“Personally modest and always softly spoken, he was a titan amongst world statesman who saw wrong and righted it and who witnessed evil and always fought it.
“Even in his later years he fought against poverty, injustice and war with all the vigour of youth and I had the privilege of working with him in recent times.”