U.S. President-elect Joe Biden has long been preparing to become the commander-in-chief of the world's most powerful country, building upon his vast experience on the global stage as a two-term vice president and longtime senator.

But even for the 77-year-old seasoned politician, it may not be an easy job to pick up the pieces of what he views as President Donald Trump's "broken" foreign policy, driven by an "America First" approach that has left the United States alienated amid battered diplomatic credibility and fraying alliance relationships.

Experts on Asian foreign and security issues warn that it may take time to overcome skepticism among allies that Washington can be trusted to honor its international and regional commitments, while the Biden administration will also face challenges in pursuing a multilateral approach to counter China.