India is set to overtake China as the world's most populous country by the end of June, U.N. estimates showed Wednesday, posing huge challenges to a nation with creaking infrastructure and insufficient jobs for millions of young people.

The seismic shift will see India's population hit 1.4286 billion -— almost three million more than China's 1.4257 billion — at mid-year, the United Nations Population Fund's State of World Population report forecast.

China has generally been regarded as the world's most populous country since the fall of the Roman Empire but last year its population shrank for the first time since 1960, while India's has continued to rise.