Regulatory concerns over the project have been reduced to almost zero, CEO said.

Move marks the first time a US government agency has included copper on one of its official “critical” lists, following the examples of the European Union, Japan, India, Canada, and China. 

The partners spent years mired in a tussle over development of the Oyu Tolgoi mine which is the country's biggest foreign investment.

Despite the personnel moves, there aren’t yet signs of permanent retrenchment among hedge funds in metals.

Apart from Asia and Oceania, all other regions outside China recorded increasing levels of activity.

The foreign ministry would agree on a UK-Zambia Green Growth Compact, aimed at generating £2.5 billion pounds of British private sector investment.