Russia`s Prime Minister Vladimir Putin said on Wednesday gas transit to Europe may stop at the end of June or in early July if Ukraine does not pay for pumping the gas into underground storage, Reuters reported.

"Gazprom will only supply the gas which has been prepaid. Without the gas pumped into storage Ukraine will simply not survive and will be forced to take gas destined for transit," Putin told a news conference in Helsinki.

"This may lead to a stoppage of gas transit to Europe in the end of June or start of July," Putin said.