Chinese official shouts an awkward #G20 start for U S , China, A Chinese official aggressively tried to stop US National Security Advisor Susan Rice from joining President Barack Obama's motorcade, after Air Force One landed in China for the G20 summit.

According to Reuters news agency, the US Secret Service had to intervene after an unidentified Chinese official stepped forward after Rice passed a barricade set up to stop the news media approaching the US president's convoy at Hangzhou airport.

The ceremonial niceties were marred by undiplomatic shouting on the tarmac as the US president embarked on a final bout of delicate overseas diplomacy before his successor is elected in November.

The ceremonial niceties were marred by undiplomatic shouting on the tarmac as the US president embarked on a final bout of delicate overseas diplomacy before his successor is elected in November.

The stakes are high for China to pull off a trouble-free G20 summit of the world's top economies, its highest profile event of the year, as it looks to cement its global standing and avoid acrimony over a long list of tensions with Washington.