U.S., China to co-operate on North Korean nuclear threat

— President Barack Obama and Chinese President Xi Jinping pledged Thursday to co-operate to confront the North Korean nuclear threat while working to narrow persistent differences over cybersecurity, human rights and maritime conflicts.

Opening a global nuclear security summit in Washington, Obama also joined leaders of Japan and South Korea in calling for further joint steps to deter North Korea. The display of diplomatic unity came as world leaders sought to ramp up pressure on the insular country’s government after worrisome nuclear provocations.

“President Xi and I are both committed to the denuclearization of the Korean Peninsula,” Obama said as he and Xi sat down for a meeting on the sidelines of the summit. “We’re going to discuss how we can discourage actions like nuclear missile tests that escalate tensions and violate international obligations.”

The Obama administration was encouraged by China’s role in passing new stringent UN sanctions punishing the North, and was urging Beijing to implement those sanctions dutifully.

Yet in a nod to deep tensions between the U.S. and China, Obama said he also planned to raise thornier issues during their meeting — including the disputed South China Sea, where China is asserting territorial claims despite competing claims by neighbours.

The U.S. said a strengthened nuclear security agreement among nations was finally set to take force following ratification by a critical mass of countries.

The stricter rules include new criminal penalties for smuggling nuclear material and expanded requirements for securing materials and nuclear facilities worldwide.

Canada has long been the subject of global criticism for its reliance on weapons-grade highly enriched uranium (HEU) to produce medical isotopes at Chalk River, about 160 kilometres northwest of Ottawa.

However, the Conservative government agreed to phase out production at the last nuclear security summit in 2014.