China will not hesitate to reduce its assistance to North Korea if it goes through with already-announced nuclear tests, says one of Beijing's most influential newspapers.
The Global Times editorial followed North Korea's defiant response to tighter United Nations sanctions, imposed for its long-range missile launch in December last year.
North Korea has issued another warning a day after announcing plans for a third nuclear test, the BBC reports.
In a statement, Pyongyang pledged "physical counter-measures" against South Korea if it participated in the UN sanctions regime.
The threat came 24 hours after North Korea said it would proceed with a "high-level" nuclear test in a move aimed at "arch-enemy" the US.
The White House criticised the move as "needlessly provocative".
North Korea has conducted two nuclear tests in the past, in 2006 and 2009. It gave no time-frame for its third test.
Its announcement followed the adoption by the United Nations Security Council of a resolution condemning North Korea's recent rocket launch and extending sanctions.
North Korea says its rocket launch was for the sole purpose of putting a satellite into orbit; the US and North Korea's neighbours say it was a test of long-range missile technology banned under UN resolutions.
