Martti Ahtisaari, the former president of Finland who was awarded the Nobel Peace Prize in 2008 for his work to resolve international conflicts, has died aged 86.

The foundation he created for preventing and resolving violent conflicts said he had died on Monday.

It said it was “deeply saddened by the loss of its founder and chair of board”.

Finland’s President Sauli Niinisto said in a statement: “It is with great sadness that we have received the news of the death of President Martti Ahtisaari.

“He was president in times of change, who piloted Finland into a global EU era.”

In 2021, it was announced that Mr Ahtisaari had advanced Alzheimer’s disease.

Among his most notable achievements, Mr Ahtisaari helped reach peace accords related to Serbia’s withdrawal from Kosovo in the late 1990s, Namibia’s bid for independence in the 1980s, and autonomy for Aceh province in Indonesia in 2005.

He was also involved with the Northern Ireland peace process in the late 1990s, being tasked with monitoring the IRA’s disarmament process.

When the Norwegian Nobel Peace Committee honoured Nr Ahtisaari in October 2008, it cited him “for his important efforts, on several continents and over more than three decades, to resolve international conflicts”.

Mr Ahtisaari – who was the Nordic country’s president for one six-year term from 1994 until 2000 – later founded the Helsinki-based Crisis Management Initiative, aimed at preventing and resolving violent conflicts through informal dialogue and mediation.

The Namibian government was grateful for Mr Ahtisaari’s work and later made him an honorary citizen of the country.

He was elected president of Finland in 1994 for a six-year term, becoming the first Finnish head of state to be elected directly instead of through an electoral college.

Mr Ahtisaari was a keen supporter of the European Union and Nato which Finland joined in 1995 and 2023 respectively.

His international highlight came in 1999 when he negotiated – alongside Russia’s Balkans envoy Viktor Chernomyrdin – the end to fighting in the Yugoslav province of Kosovo. Mr Ahtisaari also hosted the Russian president Boris Yeltsin and US counterpart Bill Clinton at a summit in Finnish capital, Helsinki, in March 1997.

Mr Ahtisaari “had a great heart, and he believed in the human being”, Mr Niinisto said.

The President added: “In his speech at the Nobel celebration, Ahtisaari said that all conflicts can be resolved: ‘Wars and conflicts are not inevitable. They are caused by humans.’

“There are always interests that war promotes. Therefore, those who have power and influence can also stop them.”

After the Finnish presidency, Mr Ahtisaari was offered several international positions, including in the United Nations refugee agency, but decided instead to open his own office in Helsinki which has centred on mediating in international crises.

Mr Ahtisaari is survived by his wife Eeva and their adult son.

He will be laid to rest in a state funeral, officials said, with the date to be announced later.