LONDON (AP) — The U.S. hopes Russia will play a constructive role in the May 25 presidential election in Ukraine, but if Moscow or its proxies disrupt it, the U.S. and European Union will move to impose heavier economic sanctions, Secretary of State John Kerry said Thursday.

“I’m not going to get into announcing today what the sanctions are,” Kerry said following a meeting in London with his counterparts in Britain, France, Germany and Italy. “We have completed our work. We know what they are. … If they have to go into effect, they will have an impact.”