US Senator John Kerry on Tuesday urged the international community to have an "absolutely serious" response to North Korea's nuclear test, on a visit to China partly devoted to non-proliferation.
"I think it's important for the world community to be absolutely serious in its response," Kerry, chairman of the US Senate's foreign relations committee, told reporters.
"Not only does North Korea and its programme hang in the balance of what we decide to do but this will have a profound effect on what the Iranians believe the world is going to do and how serious non-proliferation efforts will be."
Kerry, speaking to reporters before giving a speech at a clean energy forum in Beijing, is in China on a trip focused on climate change as well as nuclear non-proliferation issues concerning North Korea and Iran.
He said the world needed to have China -- an ally and neighbour of North Korea -- as a partner in its response to Pyongyang's nuclear bomb test on Monday.
The UN Security Council has unanimously condemned North Korea for testing the bomb while major powers are mulling fresh punitive action and US President Barack Obama has pledged support to Pyongyang's neighbours.