The unprecedented stance comes one day after the United States set goals for the power sector to reduce its own emissions, suggesting a breakthrough in climate change talks for two of the world’s largest emitters of greenhouse gases.

China, which emits the most greenhouse gas in the world, will set the cap as part of a larger five-year plan, according to a Reuters report. He Jiang, chairman of China’s Advisory Committee on Climate Change, made the announcement at a conference in Beijing.

By setting an absolute cap, China aims to better regulate and control the amount of carbon emissions in the country’s coal-reliant economy.

The cap level to be set, however, is not yet clear. A number will potentially be decided upon next year.

Both announcements by China and the United States come ahead of worldwide climate talks slated to take place in Germany beginning Wednesday.