Nepal has ordered a new survey of Mount Everest to end the "confusion" over the exact height of the world's tallest mountain, a government spokesman has said.
The official overall height of Everest is designated as 8,848m (29,029ft).
But China and Nepal have had a long-running disagreement over the height.
The Chinese have argued it should be measured by its rock height. Nepal said it should be measured by its snow height - which is four metres higher.
The world's highest mountain traverses the border of the two countries.
Last year the two sides agreed that Mount Everest should be recognised as being 8,848m tall.
But Nepal government spokesman Gopal Giri told AFP news agency that, during border talks between the two countries, Chinese officials often use the rock height.
"We have begun the measurement to clear this confusion. Now we have the technology and the resources, we can measure ourselves," Mr Giri said.
"This will be the first time the Nepal government has taken the mountain's height."
He said stations will be set up at three different locations using the global positioning system, and the task of measuring the peak would take two years.
Correspondents say that while thousands of people have climbed the mountain since the first ascent in 1953 by Sherpa Tenzing Norgay and Edmund Hillary, its exact height has been disputed ever since the first measurement was made in 1856.
The broadly-accepted height of 8,848m was first recorded by an Indian survey in 1955.
But geologists say that the estimates of both countries over the height of Mount Everest could be wrong.
They say that the mountain is becoming higher as India is gradually pushed beneath China and Nepal because of shifting continental plates.
In May 1999 an American team used GPS technology to record a height of 8,850m - a figure that is now used by the US National Geographic Society, although it has not been officially accepted by Nepal.
© Kieron Nelson 2011"Vanishing Cultures Photography"