Russian President Vladimir Putin was in Harbin on Friday to promote trade ties between the two nations on the final day of his state visit in China.

Lying just a few hundred kilometres from the border with Russia, Harbin has long served as a key hub for cross-border trade and cultural exchange.

The Russian president attended the opening ceremony of a China-Russia trade expo and was accompanied by Vice President Han Zheng.

Speaking at the ceremony, Putin hailed energy ties between the two countries and promised to "strengthen" them.

"Russia is ready and able to continuously power the Chinese economy, businesses, cities and towns with affordable and environmentally clean energy," he said.

"As the world is on the threshold of the next technological revolution, we are determined to consistently deepen bilateral co-operation in the field of high technologies and innovations," he added.

Putin arrived in Beijing on Thursday on his first trip abroad since his March re-election, meeting President Xi Jinping for talks in which the leaders framed their nations' ties as a stabilising force for the world.

The two men later ditched their ties for a less formal meeting over tea at the Zhongnanhai leadership compound. Footage from broadcaster CCTV also showed the leaders embracing.

An editorial in the Global Times newspaper on Friday cited the importance of burgeoning trade ties between the two countries, saying China had been Russia's largest trading partner for 13 straight years.

"These achievements are not easy and have been achieved by both countries overcoming various external challenges and unfavourable factors, highlighting the solid foundation of the China-Russia relationship," the editorial said. (AFP/Reuters)