Entitled Replacement Migration: Is It a Solution to Declining and Ageing Populations?, the plan seeks to "offset population decline and population ageing resulting from low fertility and mortality rates."

It contends that mass migration to the west is needed for governments to maintain "many established economic, social and political policies and programmes".

The strategy document sets out six potential scenarios for each country or region of the world necessary to meet this goal.

Under the most severe scenario, large numbers of migrants will be required to "maintain the potential support ratio" (of a population) at the highest level.

In the case of the United States, under the most extreme scenario, the report states, "It would be necessary to have 593 million immigrants from 1995 to 2050, an average of 10.8 million per year."

"By 2050, out of a United States total population of 1.1 billion, 775 million, or 73 per cent, would be post 1995 immigrants or their descendants," adds the report.