China's President Xi Jinping looks on during the BRICS Summit in Johannesburg, South Africa, July 26, 2018. Gulshan Khan/Pool via REUTERS

SHANGHAI (Reuters) - Chinese President Xi Jinping is set to visit Pyongyang next month at the invitation of North Korea leader Kim Jong Un to attend the celebrations of the 70th anniversary of North Korea’s founding, Singapore’s Straits Times newspaper reported.

It will be the Chinese leader’s first visit to the North Korean capital since he took power in 2012, and 13 years after the last visit by a Chinese President, when Xi’s predecessor Hu Jintao visited in 2005, the newspaper said on Saturday.

The Straits Times did not say where it obtained the information and the Chinese foreign ministry did not immediately respond to a request for comment.

North Korea’s celebrations are set to take place on Sept. 9 and the Straits Times said that Xi’s visit could still be subject to last-minute changes.

China is the reclusive country’s most important trading partner and Kim has visited China three times so far this year during which he has held talks with Xi on improving cooperation between the two countries and economic reforms.

The United States has stepped up sanctions on North Korea to pressure Pyongyang to give up its nuclear program. This week, the United States imposed sanctions on Chinese firms for exporting alcohol and cigarette products to North Korea in breach of those sanctions.