Manila: China has refused a visit from the Philippine vice-president to ask for mercy for a Filipino on death row, and said the man's execution will not be delayed, the Philippine foreign department said on Saturday.

The 35-year-old from the Philippines is scheduled to be executed on December 8 after he was caught at an airport in 2008 trying to smuggle about 1.5 kilogrammes of heroin into China from Malaysia.

"We have also been informed that the Chinese side is unable to arrange the visit of Vice President (Jejomar) Binay to China at this time. We respect the Chinese law and the verdict of the Supreme People's Court," the foreign department said in a statement. "We are still hoping that Vice President Binay be allowed by the Chinese authorities to go to Beijing to personally hand over the letter of appeal of President (Benigno) Aquino," it added.

In a separate statement, Binay said "I remain optimistic. I feel that Beijing has not totally closed its doors to my visit so I can personally hand over the appeal of President Aquino."

The Philippines had said earlier this week that it planned to send Binay to China to ask that the man's death sentence be commuted to life imprisonment.

Binay went on a mission to China in February to save three Filipino drug mules from death row, and secured a temporary stay of execution, but Beijing went ahead with the executions a month later.

They triggered widespread condemnation in the Catholic Philippines, where capital punishment was abolished in 2006.