US Secretary of State John Kerry and Russian Foreign Minister Sergey Lavrov will meet in London Friday to discuss the Ukraine crisis. DEBKAfile: This is a last-ditch bid for an understanding between the two powers two days before the Crimean referendum causes its secession to Russia. In Washington, Ukraine interim PM Arseniy Yatsenyuk went from meeting to meeting with President Obama, John Kerry and US lawmakers. The interim regime was branded illegitimate by Moscow.