The leaders of China and the US have attended a ceremony with the UN Secretary General Ban Ki-moon, while formally signing their countries up to the Paris climate agreement. Despite all the smiles and handshakes, not everything was rosy. As soon as Obama landed in China, the US president declared Beijing must avoid flexing its muscles in the South China Sea.<br /><br />RT LIVE http://rt.com/on-air<br /><br />Subscribe to RT! http://www.youtube.com/subscription_center?add_user=RussiaToday<br /><br />Like us on Facebook http://www.facebook.com/RTnews<br />Follow us on Twitter http://twitter.com/RT_com<br />Follow us on Instagram http://instagram.com/rt<br />Follow us on Google+ http://plus.google.com/+RT<br />Listen to us on Soundcloud: https://soundcloud.com/rttv<br /><br />RT (Russia Today) is a global news network broadcasting from Moscow and Washington studios. RT is the first news channel to break the 1 billion YouTube views benchmark.