WARSAW, Poland (AP) — President Joe Biden has closed out his wartime visit to Europe by working to shore up partnerships with allies perched on NATO’s perilous eastern flank. At the same time, Russia’s Vladimir Putin is drawing closer to China as his invasion of Ukraine nears the one-year mark. Biden met with leaders of the Bucharest Nine nations in Warsaw on Wednesday at the conclusion of a whirlwind, four-day visit to Ukraine and Poland meant to reassure allies of U.S. support. In dramatic counterpoint, Putin met with the Chinese Communist Party’s most senior foreign policy official. The flexing of alliances was an indication that both sides are digging in for prolonged conflict in Ukraine with fighting expected to intensify as spring arrives.