Hollywood star Angelina Jolie and British Foreign Secretary William Hague on Tuesday launched a four-day summit on ending rape in war, calling for an end to the "culture of impunity" and more prosecutions.

US Secretary of State John Kerry, who will attend the conference in London on Friday, said the delegates from 117 countries wanted to "relegate sexual violence to the annals of history".

The summit is the fruit of a two-year campaign by UN special envoy Jolie and Hague, who have visited the Democratic Republic of Congo and Bosnia to meet victims of rape during conflict.

As she opened the conference, Jolie said she and Hague had discussed a woman they met in Bosnia, who was still too ashamed to tell her son that she had been raped.

"This day is for her," said Jolie. "We believe it truly is a summit like no other." Standing next to her, Hague told reporters: "This will be the greatest concentration of effort, of discussion and decision ever seen in combating sexual violence in conflict."

The conference, held at a vast conference centre, includes 150 events open to the public in what the organisers hope will be a giant exercise in raising awareness. In a statement, Kerry called for countries to end their protection of individuals who commit "these vile acts".

"We must declare in unison: 'They can't run and they won't hide here'," he said. Almost 150 governments have endorsed a declaration of commitment to end sexual violence in conflict. Organisers also want to increase and improve the documentation of rape in warzones to allow more prosecutions to be brought.