BEIJING (Reuters) - China’s Defense Ministry on Friday denied reports that Chinese troops were massing on the North Korean border, ahead of a possible fifth North Korean nuclear test, saying its deployments there were normal.

The Hong Kong-based Information Center for Human Rights and Democracy said earlier this week that China had sent 2,000 troops to the border, a story picked up by Russian and Iranian news outlets, among others.

The decision was made ahead of the expected testing of North Korea’s fifth nuclear device, the report said, in violation of U.N. sanctions.

“The relevant report does not accord with the facts,” the Defense Ministry said in a short statement. “The Chinese military maintains normal combat readiness and training on the China-North Korea border.”

It did not elaborate.

Reports periodically surface about unusual troops movements on the border, which are hard to verify independently and generally quickly denied by the Chinese government.

North Korea has vowed to conduct further nuclear tests, despite stepped up international sanctions.

Some experts expect North Korea to conduct a fifth nuclear test in the near future, possibly before a ruling party congress in early May, following an embarrassing failure of a test of an intermediate-range missile earlier this month.

China is North Korea’s most important economic and diplomatic backer, but has been infuriated by North Korea’s nuclear and missile tests and has signed on for tough U.N. sanctions.

North Korea and the rich, democratic South are still technically at war after the 1950-53 conflict ended in an armistice, not a treaty. China and North Korea fought side-by-side against a U.S.-backed South Korea, which joined forces under the U.N. flag.

The North routinely threatens to destroy South Korea and the United States.