MOSCOW (Reuters) -Here is a look at how U.S. sanctions on Russian oil firms Rosneft and Lukoil, which take effect at 1701 GMT on Friday, may affect the Russian foreign currency market. Ahead of the deadline, the rouble was strengthening on reports about a U.S.-drafted plan to end the war in Ukraine,​ which if implemented, could mean the sanctions are cancelled. WHAT HAS BEEN HAPPENING ON RUSSIA'S FOREX MARKET? The market was hit last year by sanctions on Russia's main operator, the ‌Moscow Exchange (MOE ...