By Valerie Volcovici

NEW YORK (Reuters) - Leaders of 11 Chinese cities and provinces are to announce that their carbon emissions will start to fall earlier than China's national target of 2030 at a U.S.-China meeting on Tuesday, a move meant to build momentum for a global climate change accord in December.

Those announcements, as well emission-reduction commitments from more than a dozen U.S. states and cities, will form part of a joint declaration that municipal and regional leaders from the world's two biggest greenhouse gas emitting countries will sign during a U.S.-China meeting on low-carbon cities in Los Angeles on Tuesday and Wednesday.

The summit builds on a key climate change deal reached last November between U.S. President Barack Obama and Chinese President Xi Jinping in which the United States agreed to lower greenhouse emissions as much as 28 percent below 2005 levels by 2025, and China pledged that its emissions would peak by 2030, according to the White House.

"The commitments that the Chinese and American cities are taking ... are a very important component of our broader efforts to deepen climate cooperation and to show that ... the two largest emitters in the world are taking seriously our obligation to meet the ambitious goals that we set out last year," said Brian Deese, a senior adviser to Obama.

Xi is visiting the United States next week, at a time when both countries are sparring over cybersecurity, an issue Obama is expected to raise.

But climate change is one area where the two countries largely see eye to eye, a fact the White House is happy to highlight.

Deese said the actions that local leaders will announce were meant to demonstrate how both countries can implement the national targets they pledged jointly last year.

Two of China's biggest cities, Beijing and Guangzhou, have committed to a peak for their carbon dioxide emissions by 2020, 10 years earlier than the national target. Others, including Shenzhen, have pledged to peak by 2022.

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Cities and provinces that have made such commitments have formed an Alliance of Peaking Pioneer Cities, which represents one-quarter of China’s urban carbon emissions, or the equivalent of all Japan's or Brazil's emissions, according to the White House.

Some of the biggest critics of President Obama's climate change strategy in the U.S. Congress had criticized his agreement with Xi last year. Republican Senate Leader Mitch McConnell said the pact “requires the Chinese to do nothing at all for 16 years" while U.S. states were forced to cut their emissions.

Cities including Los Angeles, Houston and Atlanta as well as states such as California and Connecticut also re-affirmed a variety of climate change goals, including emission-reduction targets, mandates to expand renewable energy, and slashing the use of transportation fuels.

(Reporting By Valerie Volcovici; additional reporting by Jeff Mason; Editing by Kevin Liffey)