Cliff Owen, Associated Press
Secretary of State John Kerry gestures while participating in the Sixth Annual Washington Ideas Forum in Washington, Thursday, Oct. 30, 2014. Kerry says the United States and China must work together to stave off a global catastrophe from climate change. He appealed for greater cooperation between the two world powers.

WASHINGTON — Secretary of State John Kerry says the United States and China must work together to stave off a global catastrophe from climate change. He appealed for greater cooperation between the two world powers.

In a speech Tuesday, Kerry praised Chinese help on combating nuclear proliferation by Iran and North Korea. He also welcomed a growing China role in Afghanistan.

But Kerry made clear the U.S. wouldn't back down over its differences with China on cyber-espionage, human rights violations and maritime security disputes in the South China Sea.

Kerry travels to Beijing Friday, ahead of a visit by President Barack Obama for a regional summit and talks with Chinese President Xi Jinping (shee jihn-peeng).

Kerry was speaking at the Johns Hopkins School of Advanced International Studies.