The format of the OSCE Minsk Group on the Nagorno Karabakh conflict settlement should not be changed, President of the OSCE PA Goran Lennmarker said in Yerevan. Any change of the format may slow down the settlement process, he said adding he doesn't agree with statements on increase of tension in the Nagorno Karabakh region. However, he pointed out at casualties at the front line and stressed the necessity of an agreement.