China becomes Japan's biggest trading partner in both exports and imports in the first six months this year, as the global economic downturn affected Japan-U.S. trade more seriously, the Japan External Trade Organization (JETRO) said Wednesday.

Exports to China fell 25.3 percent from a year earlier to 46.5 billion dollars and imports from the country dropped 17.8 percent to 56.2 billion dollars, however, trading with other countries and regions including the United States showed larger declines, JETRO said in its report.

It is the first time exports to China surpassed those to the United States.

In the January-June period, the trade with China accounted for 20.4 percent of the total trade volume of Japan, while that with the United States accounted for 13.7 percent and that with South Korea 6.1 percent.

JETRO also projected a decline of Sino-Japanese trade for the whole year of 2009, the first yearly contraction since 1998 Asian financial crisis.