North Korea vowed Tuesday to bolster its nuclear deterrent and take “self-defence” measures unless the United States halts criticism and pressure over its rocket launches and atomic programme. A foreign ministry spokesman was hitting back at a statement Saturday from Washington and other Group of Eight nations, which condemned Pyongyang’s April 13 long-range rocket launch. The G8 said it would press for United Nations action — an apparent reference to tougher sanctions — in response to any further launches or to a nuclear test. The North, in the spokesman’s statement on official media, said its nuclear deterrent was developed as a response to US hostility and “we will expand and bolster it non-stop as long as this hostile policy goes on”. It said that “from the beginning” it had not envisaged “such a military measure as a nuclear test”, since the aim of its launch was to put a scientific satellite into orbit for peaceful purposes. The UN Nations Security Council strongly condemned the failed launch as breaching a ban on testing ballistic missile technology, and tightened existing sanctions. Washington was now talking about a possible nuclear test by Pyongyang in an attempt to incite confrontation, the North’s statement said.