BEIJING, CHINA - China said Tuesday a top official has postponed a trip to North Korea, but declined to specify whether the move was in response to sabre-rattling by its Stalinist neighbour and ally.

Chen Zhili, vice chairwoman of China's national parliament, was scheduled to have visited North Korea in June, foreign ministry spokesman Qin Gang told reporters.

"Due to the schedule at home, Vice Chairwoman Chen Zhili has postponed her visit to the DPRK due in early June," Qin said, referring to North Korea by its official name - the Democratic People's Republic of Korea. He gave no other details.

South Korea's Yonhap news agency earlier reported that China had cut off official ties with North Korea over the nuclear row, but Qin said ties remained "normal."

Regional tensions have spiked since the regime of Kim Jong-Il tested a nuclear bomb for the second time on May 25, launched a series of short-range missiles, and renounced the 1953 truce ending the Korean War.

Chen was to have stopped in North Korea as part of a trip that began May 19 and also took her to Australia and New Zealand, according to the website of the National People's Congress, China's rubber-stamp parliament.

North Korea's actions have dealt a blow to China's stated ambition of achieving a nuclear-free Korean peninsula and Beijing's hosting of six-nation talks aimed at peacefully disarming the North.

China has publicly reiterated its steadfast friendship with fellow communist-ruled North Korea. This year the two nations are marking the 60th anniversary of diplomatic ties.

But recent comments in the Chinese state-run press have hinted at growing impatience with North Korea.

Qin urged countries not to "take actions that cause the situation to further deteriorate," but did not respond specifically to questions over whether Beijing would support UN sanctions or take other actions against North Korea.