BEIJING, Jan 4 (Reuters) - China will increase the area sown with corn in its main grain regions this year, the agriculture minister has said, reversing several years of declining acreage in response to a growing shortfall.

The expansion is part of a comprehensive plan to ensure food security, according to Tang Renjian, the newly appointed Minister of Agriculture and Rural Affairs, state media Xinhua news agency reported.

Authorities will focus on expanding corn acreage in the northeast as well as areas around the Yellow, Huai and Hai rivers, Tang said in an interview with Xinhua on Sunday.

The pledge comes after China's corn prices soared to record levels after authorities nearly emptied once-mammoth temporary reserves at auctions. Importers have brought in record volumes of grain to plug the shortage.

"Corn acreage and output is expected to recover and increase, while corn prices will probably fall in the next few years," said Meng Jinhui, senior analyst with Shengda Futures.

China had been cutting down on corn acreage in the past few years to whittle down the state stockpiles and to boost output of other crops like soybeans.

Farmers planted 41.264 million hectares of corn in 2020, with output of the grain at 260.67 million tonnes, according to the National Bureau of Statistics.

Authorities must also make sure that the acreage of double-crop rice that expanded in southern regions in 2020 does not decline this year, while the yield must improve, Tang said.

Wheat acreage in northwestern and areas around the Yellow, Huai and Hai rivers should strive to recover, according to Tang.

China will stabilize soybean output and secure domestic supplies of soybeans for food use, Tang added.

Tang, previously governor of the northwestern province of Gansu, was appointed minister of agriculture and rural affairs in late December, replacing Han Changfu, who held the post for a decade.

China will also focus on better seeds and on protecting its arable land to shore up grain security, he said.

(Reporting by Hallie Gu and Dominique Patton Editing by Robert Birsel)