Image copyright Reuters Image caption Most trade between North Korea and China comes across these bridges on the Yalu river.

China has issued data suggesting trade with North Korea was not as strong as implied by the United States.

It follows a tweet from Donald Trump that highlighted an "almost 40%" rise in bilateral trade between the two nations in the first quarter of 2017.

China didn't dispute that number, but state media suggested the president's comment was unfair and selective.

The US has been urging Beijing to put pressure on Pyongyang as tensions mount over Kim Jong-un's nuclear ambitions.

China is North Korea's only major ally, trading partner and aid donor.

An exception

Figures from China's Ministry of Commerce show that bilateral trade with North Korea was up 37.4% in the first three months of 2017, compared with the same period a year earlier.

That is roughly the figure President Trump quoted. But the ministry said that when the first five months of the year were taken into account, trade grew by only 13.7%.

Image copyright Donald Trump / Twitter

And over the same period, imports of North Korean goods into China fell 9.3% to $720m the ministry said.

A report in the state-controlled Global Times suggested the first three months of 2017 were an exception, and came after three consecutive years of declining trade between the two countries.

Responding to Mr Trump's tweet, the paper's editorial said: "First quarter data cannot speak for the whole year".

It added China's trade with North Korea was now roughly equal to its trade with Mongolia, which has an eighth of the population.

China has banned the import of coal, iron ore, gold and rare earth minerals, and several other raw minerals from North Korea. It has also banned sales of jet fuel to North Korea.

Sanctions

The fresh trade data was released as tensions rose following North Korea's latest test of a long-range missile, which it is believed was capable of reaching Alaska.

Image copyright Reuters Image caption North Korea launched a missile it says could reach Alaska.

President Trump and Chinese President Xi Jinping are preparing for meetings at the G20 summit in Hamburg, where North Korea's nuclear aspirations are expected to be high on the agenda.

At a press conference in Poland before the summit, Mr Trump promised to confront North Korea "very strongly" and said the US was considering "severe things".

US Ambassador to the United Nations, Nikki Haley, has indicated the US might take a tougher line on countries that have economic ties to North Korea.

China has called for restraint and made clear it did not want to be targeted by US sanctions.

Last week Washington imposed sanctions on several Chinese businesses that it claimed were supporting Pyongyang.

US authorities have also tried to seize millions of dollars from major US and European banks that might be linked to North Korea.

Prosecutors allege the banks have processed more than $700m of "prohibited" transactions since 2009.