China says it is seriously concerned about North Korean nuclear development, in the wake of a BBC interview with a top official from the North.

North Korea's vice-foreign minister told the BBC Pyongyang would continue to test missiles and would launch a pre-emptive nuclear strike if it thought the US was planning an attack.

Foreign ministry spokesman Lu Kang said China opposed words or actions that could further raise tension.

North Korea-US tension is growing.

There has been heated rhetoric from both sides in recent days. US Vice-President Mike Pence, who has been visiting the region, warned the North not to test Washington and said the US "era of strategic patience" with Pyongyang was over.

The BBC's Stephen McDonell in Beijing says the Chinese government appears to be becoming increasingly frustrated with North Korea, its traditional ally.

"I have noted the recent report," Mr Lu said, referring to the BBC interview.

"China expresses serious concern with recent trends about North Korea's nuclear and missile development.

"China is unswerving in its commitment to realising the denuclearisation of the Korean peninsula, maintaining the peace and stability of the Korean peninsula, and continue to solve matters through dialogue and negotiations."

Mr Lu added that tension was already high in the region before the latest comments from Pyongyang.

The North held a show of military might in a parade over the weekend and tested another missile on Sunday, which the Pentagon said blew up almost immediately after launch.

Pyongyang said it may test missiles on a weekly basis, and warned of "all-out war" if the US takes military action.

"If the US is planning a military attack against us, we will react with a nuclear pre-emptive strike by our own style and method," Vice-Foreign Minister Han Song-ryol told the BBC on Monday.

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Timeline of recent tensions

• 8 April: The US military orders a navy strike group to move towards the Korean peninsula
• 11 April: North Korea says it will defend itself "by powerful force of arms"
• 15 April: North Korea puts on a huge military parade - complete with missiles - to mark 105th birthday of the nation's founding president, Kim Il-sung. Meanwhile US Vice-President Mike Pence arrives in South Korea
• 16 April: North Korea conducts a rocket test, but it fails
• 17 April: Senior North Korean official tells the BBC the country will continue to test missiles "weekly" and Mr Pence warns North Korea not to "test" Donald Trump
• 18 April: It emerges the US Navy strike group was not heading towards North Korea when US officials said it was

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Later Mr Pence vowed to "defeat any attack and meet any use of conventional or nuclear weapons with an overwhelming and effective American response".

The US Navy's Carl Vinson strike group - consisting of an aircraft carrier and other warships - is on its way to the Western Pacific, Pacific Command said on Tuesday, following an order from President Donald Trump last week.

The USS Carl Vinson (left) and other warships were in the Indian Ocean over the weekend

It has emerged that when the original announcement of the group's movement was made it was travelling in the opposite direction.

It is not clear whether this was a deliberate deception, a change of plan or simple miscommunication, the BBC's Korea correspondent Stephen Evans says.