WASHINGTON - President Joe Biden on Friday is set to host the first in-person gathering of leaders of an Indo-Pacific alliance known as "the Quad" as he wraps up a difficult week of diplomacy after facing no shortage of criticism from allies and adversaries.The White House meeting with leaders from India, Japan and Australia gives Biden a chance to put the spotlight on a chief foreign policy goal: greater attention to the Pacific in light of what the United States sees as China’s coercive economic practices and unsettling military maneuvering in the region.The leaders are expected to announce a coronavirus vaccine initiative, plans to bolster semiconductor supply chains and a program to bring graduate and doctoral students in STEM fields to.