North Korea says a heatwave is threatening a "natural disaster" and has called on its citizens to help protect crops from drought.

The Korean peninsula is experiencing record temperatures and South Korea has reported 28 deaths from the heat.

In the North, which has previously suffered bouts of famine, state media warned that key crops such as rice and corn were under threat.

It called on citizens to "join the struggle" to safeguard harvests.

"This year's high temperature is an unprecedented natural disaster but it is not an insurmountable difficulty," it said.

"Officials and working people in all fields and units... should turn out as one and devotedly work out of patriotism in the campaign to prevent damage by high temperature and drought," an editorial in the state-run newspaper Rodong said.

"All people should fully display their patriotic zeal in the ongoing campaign."

State news agency KCNA said irrigation equipment was being urgently repaired and new wells and reservoirs created.

"Myriads of water carriers, tractors, trucks and other vehicles have been involved in irrigating croplands together with all the available watering equipment and devices," it said.

Temperatures in the capital Pyongyang hit a record high of 37.8C (100F) on Wednesday. The South's capital, Seoul, also recently recorded its hottest ever temperature at 39C.

Earlier this year, the head of the UN's World Food Programme made a rare visit to North Korea and said the country was working hard to meet nutritional standards.

David Beasley spent two days in the capital, Pyongyang, and two outside it, accompanied by government minders.

He said levels of hunger were not as high as in the 1990s. Hundreds of thousands of people are believed to have died in a widespread famine in the North between 1994 and 1998.

"I didn't see starvation like you had in the famine back in the 1990s, that's the good news. But is there a hunger issue, is there under-nutrition? There's no question about it," he told the BBC.

After a drought in 2017, the UN said seven in 10 North Koreans were relying on food aid, while four in 10 were malnourished.

North Korea is under strict UN sanctions over its nuclear and ballistic missile programmes, despite a recent diplomatic rapprochement with the US.

Decades of state mismanagement and a lack of infrastructure have left the country vulnerable to natural disasters such as floods and drought.