President Xi Jinping encouraged people of an ethnic minority group in remote southwest China to raise morale and work together for a better life.

President Xi made the remarks after he received a letter from people of the Dulong ethnic minority group in Yunnan Province just before New Year's Day, said a statement from the general office of the Communist Party of China (CPC) Central Committee on Friday.

The letter informed Xi that a long-awaited highway tunnel linking the mountainous home of the Dulong people with the outside world is about to be completed.

Xi said he is very glad to hear the good news about the tunnel and congratulated the Dulong people.

He said he is always concerned about the well-being of the Dulong people as they have lived harsh lives.

"Under the leadership of local party and government departments and with the help of the whole society, I hope you will be positive in the face of difficulties, take care of your livelihood and work harder to reduce poverty. I hope you will live a 'moderately prosperous' life together with other ethnic groups as early as possible," Xi wrote.

The Dulong ethnic group, with a population of about 4,000 people, lives along the deep gorges of the Dulongjiang River in the northwestern part of Yunnan Province bordering Myanmar.

A highway passing through the high mountains along the river is the only link between their home and the outside, but transport is cut off for at least half a year due to heavy snowfall on the mountains. Geographic isolation has left this area the least developed in Yunnan and the whole of China.

Xi gave instructions on helping small ethnic groups like the Dulong. In the past few years, the Yunnan government has tried hard to improve local infrastructure.

A six-km-long tunnel through the mountains is aimed at bypassing a 20-km-long section of highway that is affected by snowfall. If it is completed, the Dulong people will no longer be isolated.