A great humanitarian rescue 80 years ago during World War II and the wartime friendship of Chinese and British people forged in the joint fight against fascism have connected Denise Wynne from the United Kingdom with President Xi Jinping.

Wynne wrote to Xi to express her gratitude to the Chinese people for rescuing her father, Dennis Morley, from a cargo ship that sank in the East China Sea in 1942, and she expressed her staunch support for building on the friendship between generations of the British and Chinese people.

The president recently wrote a letter of reply, encouraging family members of the survivors to further work on bilateral friendship, according to an official release on Saturday.

Xi said he looks forward to more British friends contributing to China-UK relations.

In October 1942, the cargo vessel Lisbon Maru was requisitioned by the Imperial Japanese Army to carry more than 1,800 British prisoners of war, as well as weapons and army rations, from Hong Kong to Japan.

The ship was hit by the US Navy off the Zhoushan Islands, Zhejiang province, and the Japanese tried to prevent the prisoners from escaping before abandoning the ship. A total of 843 people died, while 384 others were rescued by local fishermen.

Xi knows this part of history well, as he mentioned it during his state visit to the UK in 2015.

In his recent letter to Wynne, Xi wrote that the touching story of heroic Chinese fishermen from Zhoushan coming to the rescue is "an important testimony" to China and the UK fighting shoulder to shoulder as allies against fascist aggression during World War II, and it is also a historical episode epitomizing the profound friendship forged between the peoples of the two countries.

This year marks the 50th anniversary of the establishment of ambassadorial-level diplomatic relations between China and the UK.

China-UK annual trade in commodities has increased from $300 million in 1972 to $100 billion last year, and China has become the largest source of commodity imports for the UK.

Xi attributed the bilateral relationship's lasting progress over the past five decades to "the hard work and dedication of numerous friendly personnel from both countries", expressing his hope that more British friends could promote the development of the ties.

On Friday, Chinese Ambassador to the UK Zheng Zeguang paid a visit to Wynne at her home in Chalford, Gloucestershire, England, to deliver Xi's letter of reply.

Zheng said Xi's letter fully manifests the great importance that he attaches to the friendship between the Chinese and British people and his people-first and pragmatic leadership style.

This is a great inspiration to people from all walks of life in the UK who are committed to promoting China-UK friendship, he said.

Wynne, who said that she felt "really honored and very, very pleased to receive the letter" from Xi, said that she wrote to him "to remember the fishermen and the prisoners of war, and their courage".

"My father did say he owed his life to the Chinese fishermen," she said.

Wynne expressed her hope to travel to Zhoushan in the near future to meet the families of the fishermen who participated in the rescue and to revisit the historical stories of the friendship between the Chinese and British people.

Major Brian Finch, who has been collecting historical documents on the Lisbon Maru and is a friend of Wynne's, said "the story contains the very worst and the very best of humanity".

"The amazing self-sacrifice, both from the Chinese fishermen and also from some of the prisoners helping others, was absolutely outstanding and unbelievable, as was the cruelty of the fascists," he said.

This touching history is worth remembering, and the China-UK friendship in the fight against fascism should be passed down from generation to generation, he added.

Observers said Xi's letter illustrates the great importance attached by Beijing to bilateral relations with the UK and China's sincerity to take these relations forward despite some recent frustrations.

"Given the fact that an increasing number of people are not aware of the wartime past and some politicians are even whitewashing fascists' cruelty, this bilateral friendship, which testifies to the history of jointly combating fascism, deserves to be known by more ordinary people," said Tian Dewen, deputy director of the Chinese Academy of Social Sciences' Institute of European Studies.

Over the past 50 years, the two countries have reaped fruitful outcomes in areas such as investment, culture, education and sports, Tian noted.

Seeking a complete decoupling with China or being tough against China in a geopolitical context does not serve the interests of the UK, he said.

"While London is faced with thorny issues including soaring inflation and troubling relations with the European Union, its healthy pragmatic cooperation with China could play a constructive, conducive role in easing such difficulties," Tian said.