(CNN) China will face an "unstoppable" population decline over the coming decades, with fewer and fewer workers struggling to support an increasingly aging society, according to a report by a leading state-sponsored Chinese thinktank.

The report, which comes more than three years since China officially ended its controversial decades-long one-child policy, warns that the "the era of negative population growth is almost here," forecasting that the country's population will peak at 1.44 billion in 2029.

The Chinese Academy of Social Sciences report suggests that the decline in fertility rates will lead to a decrease in overall population to 1990-era levels of 1.172 billion by 2065. World Bank data from 2017 showed a Chinese population of 1.386 billion.

The country's working-age population has stagnated, the report states, while its dependency ratio -- the number of working people in relation to non-working, largely children and retired people -- continues to skew.

"In theory, long-term population decline, especially accompanied with the increasing escalation of aging of population, is bound to bring very negative social and economic consequences," the report states, without elaborating on what these consequences could entail.

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