Hong Kong's government says it needs to build billions of dollars' worth of artificial islands to give the city's glittering skyline room to grow, but critics say developers are hoarding unused land that could solve the problem.

Hong Kong Chief Executive Carrie Lam estimates the 1,111-sq.-km city needs another 1,200 hectares, or about 12 sq. kilometers, and has proposed creating new land offshore.

Her plan, which would cost up to $64 billion, could exhaust half of the financial hub's sizable financial reserves.