US, China boost ties with new farm deal

US and Chinese officials are set to sign a new five-year contract boosting agricultural ties between the world's two largest economies.

The announcement coincided with a rare US visit by Chinese Vice President Xi Jinping as well as the launch of the first U.S.-China Agricultural Symposium in Bejing on Thursday. 

Bloomberg reported the announcement as Xi, seen as China's president-apparent, visited an Iowa corn and soybean farm on Thursday, his third day of a four-day US visit. 

US Agriculture Secretary Tom Vilsack hailed the agreement as one that reflects the “rapid development of China-US agricultural cooperation and trade."  

"We want to continue building those cooperative relationships and public-private partnerships," said Vilsack, who is set to sign the agreement later Thursday with Chinese agriculture minister Han Changfu.

The US is the largest exporter of agricultural products in the world and China its biggest customer at $22 billion in 2011. The Asian giant has also seen record crop harvests over the past five years, while Iowa is the largest US producer of key exports like corn and soybeans.

Thursday's announcement follows a strong call for greater US-Chinese cooperation made by Xi in Washington on Wednesday. 

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Xi has used his US visit to call for "strategic" collaboration between the two world powers. His visit has also been an opportunity for fresh debate on China, whose currency policy is often criticized by US lawmakers as unfairly favoring Chinese domestic industry. 

Presidential hopeful Mitt Romney, who is waging a tough fight for the Republican nomination, critiziced Obama's China policy in an op-ed published in The Wall Street Journal on Thursday, painting the US leader as a "supplicant" to China, which he described as a "prosperous tyranny."

Romney's article prompted a strong rebuttal from the White House.