China has proposed building a railway under Mount Everest that will link the country with Nepal. It’s the latest in a series of Chinese railway project proposals that reflect a growing Chinese presence in Nepal, the Guardian reports.

The line would be an extension of the preexisting Qinghai-Tibet rail network, which links China with the Tibetan capital of Lhasa. The addition would extend the line to Kathmandu. Chinese foreign minister Wang Yi announced the project. He expects it to be completed in 2020. Details of the project are hazy, and no statement was made about its cost.

“The line will probably have to go through Qomolangma so that workers may have to dig some very long tunnels,” railway expert Wang Mengshu told the China Daily, referring to Mount Everest by its Tibetan name.

The project is under fire from rights groups such as the International Campaign for Tibet, which warns of “dangerous implications for regional security and the fragile ecosystem of the world’s highest and largest plateau.”