However, these economies are expected to recover next year with a growth rate of 7.9 percent, said the bank's economic update report, as they have remained resilient despite the lackluster performance of the global economy. The report credited growth in most economies in the region to domestic demand.
China's growth this year was projected at 7.9 percent, down from last year's 9.3 percent, the lowest growth rate since 1999 due to weak exports and the government's efforts to cool down the overheating housing sector.
However, the report said recovery had set in during the final months of 2012 and because of that, China's economy in 2013 is expected to grow at 8.4 percent, fueled by fiscal stimulus and the faster implementation of large investment projects.
"The East Asia and Pacific region is becoming increasingly important for the world economy, and is expected to contribute almost 40 percent of global growth in 2012" said World Bank Chief Economist for East Asia and Pacific Bert Hofman.
"With high growth rates sustained in the region, we expect poverty to continue to decline. The share of people living under $2 a day in the region is forecast to reach 23.3 percent by the end of 2014, down significantly from 28.8 in 2010."
Developing East Asia, excluding China, is projected to grow 5.6 percent in 2012, up from 4.4 percent in 2011. The report said the rebound in Thailand following the floods in 2011, strong growth in the Philippines, and relatively mild slowdowns in Indonesia and Vietnam contributed to the recovery. Continuing strong performances by Indonesia, Malaysia, and the Philippines will boost growth in East Asia without China 5.7 percent in 2013 and 5.8 percent in 2014.
The report said Myanmar's re-engagement with the international community helped its economy grow at 5.5 percent this fiscal year and is forecast to hit 6.3 percent in the next fiscal.
The report warned of risks that could slow the region's momentum, such as reform delays in the euro zone, the U.S. "fiscal cliff" and a possible sharp decline in the growth of investments in China.