Chinese Foreign Minister Wang Yi and two other diplomats relayed conditions for Aquino to attend the annual China-ASEAN Expo, which opens tomorrow in the southern city of Nanning, Department of Foreign Affairs spokesman Raul Hernandez told a news conference.
Hernandez declined to detail the conditions, but said these were "absolutely inimical to our national interest."
The Chinese side asked that the conditions not be publicly disclosed, he said. They were discussed by Wang and Philippine Foreign Secretary Albert del Rosario in Beijing on Wednesday.
"The president stood firm in the defence of the country's national interest," Hernandez said.
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Two Philippine officials told The Associated Press that China wanted Manila to withdraw a UN arbitration case over disputed islands in the South China Sea.
The officials spoke on condition of anonymity because they were not authorised to speak to reporters.
Chinese officials have also cited a new standoff between China and the Philippines over the Second Thomas Shoal, which is called Ayungin Shoal by Filipinos and Ren'ai Reef by the Chinese, the Philippine officials said.
China was concerned that allowing Aquino to visit after the Philippines brought its territorial disputes to UN arbitration in January which Beijing calls an "unfriendly act" may not be welcomed by the Chinese public and media, the officials said.
Asked to comment today, Chinese Embassy spokesman Zhang Hua did not react to their statements, but urged the Philippines to work with China "to overcome difficulties and disturbances and make real efforts to get the China-Philippine relationship" back on track.
The Philippines is this year's "country of Honour" at the trade fair, which takes place in China every year to highlight trade exchanges between Beijing and the 10-member Association of Southeast Asian Nations.
The Philippines and China have been embroiled in increasingly antagonistic territorial disputes.
China claims virtually the entire South China Sea and its island groups on historical grounds. The Philippines, Vietnam, Brunei, Malaysia and Taiwan have rejected that, sparking fears the disputes might spark Asia's next major armed conflict.