As goes Xi, a President Biden?

US Vice President Joe Biden on Wednesday kept alive speculation he will seek the Oval Office, joking that he asked China's new leader for tips on moving up the ranks.

Opening annual US-China talks, the famously frank Biden recalled his extensive trip to China in 2011 aimed at building a rapport with then vice president Xi Jinping, who became president in March.

"When I congratulated him on his elevation, I asked if he could possibly help me," Biden said to laughter, quickly adding that he was "kidding."

Biden, who was tapped by President Barack Obama in the 2008 election for his experience in Washington, has never denied an interest in seeking the White House himself in 2016.

But many political pundits assume that Biden is waiting for a clear indication from Hillary Clinton as he may not want to challenge the prohibitive favorite of their Democratic Party's base.

Clinton, who narrowly lost to Obama for the party nomination in 2008, would make history as the first woman president.

Biden, whose two earlier presidential bids gained little traction, could face questions about his age as he would turn 74 soon after the 2016 election.

But Biden appears to be in good health and has used his 36 years of experience in the Senate to spearhead many of Obama's signature initiatives from the economic stimulus to the US withdrawal from Iraq.