The head of the World Council of Churches has used a visit to South Korea to appeal to the country's Christians to be peacemakers.

The Reverend Dr Olav Fykse Tveit challenged Christians to believe God's promise of peace in Psalm 85 – "God will speak peace to his people" – despite the divide between South and North Korea for the last 60 years.

"Peace is something radical, something that has to be told and has to be believed, so that it may become possible," he said.

"The Korean people have been longing for a final peace to be settled, a peace that can bring life together, make life together in peace on this peninsula possible again."

He reflected on the global need for peacemakers in light of the fighting in Syria, and recently between Israel and Palestine.

"We live in a time when life is threatened, when injustices in the world are a reality, even a threatening reality," he said.

"The difference between rich and poor is growing. The unemployment of young people is growing. The consequences of climate changes are disturbing, sometimes dangerous.

"God will speak peace to his people – to give us peace, to give us rest in our restlessness with our own shortcomings and sins.

"God speaks peace to his people so that we can become peacemakers. So that we can bring the word of peace, even to make the peace others are longing for."

Dr Tveit's visit comes ahead of the WCC's 10th Assembly, taking place in Busan in the autumn.

The gathering will take place over 10 days around the theme of "God of life, lead us to justice and peace".