The leaders then turned to the conditions under which the Western Allies would open a new front by invading northern France (Operation Overlord), as Stalin had pressed them to do since 1941. Up to this point Churchill had advocated the expansion of joint operations of British, American, and Commonwealth forces in the Mediterranean, as opening a new western front had been physically impossible due to a lack of existing shipping routes, leaving the Mediterranean and Italy as viable goals for 1943. It was agreed Operation Overlord would be launched by American and British forces by May 1944 and that Stalin would support the Allies with a concurrent major offensive on Germany's eastern front (Operation Bagration) to divert German forces from northern France.