LONDON (REUTERS) - British Prime Minister Theresa May on Sunday (Sept 3) said the United Nations Security Council should urgently look at imposing new sanctions on North Korea and speed up implementation of existing ones.

Pyongyang conducted its sixth and most powerful nuclear test earlier on Sunday.

"This latest action by North Korea is reckless and poses an unacceptable further threat to the international community," Ms May said in an e-mailed statement.

"I discussed the serious and grave threat these dangerous and illegal actions present with President Abe in Japan this week and reiterate the call we jointly made for tougher action, including increasing the pace of implementation of existing sanctions and looking urgently in the UN Security Council at new measures."