At an unexpected news conference, a Philippine presidential spokesman said Aquino had sent the chairman of the Manila Economic and Cultural Office to Taiwan as his personal representative to make the apology on behalf of Aquino and the Filipino people.
Just hours after the apology, Jiang Yi-huah, chief of Taiwan's executive body, announced the initiation of the second wave of sanctions against the Philippines, with measures such as suspension of high-level exchanges between the two.
Jiang said the Philippines has not shown sufficient sincerity and has been oscillating in its handling of the case, making it necessary for Taipei to take further action, Taiwan media reported.
The new sanctions also remove the Philippines from Taiwan's visa-waiver program and suspend economic exchanges, fishery cooperation, science and technology cooperation, as well as bilateral aviation negotiations.
In Manila's news conference, spokesman Edwin Lacierda said Aquino will convey his and the Filipino people's deep regret and apology to the family of Hung Shih-cheng, the 65-year-old fishing captain shot dead last week by Filipino coast guard, as well as to the people of Taiwan over the unfortunate and unintended loss of life.
Lacierda urged Taiwan not to implement sanctions and to reverse its decision to ban new Filipino workers, AFP reported.
He did not mention compensation, but said Aquino had asked the Manila Economic and Cultural Office to make "donations" to the dead fisherman's family. He did not say how much would be donated.
Yang Baoyun, an expert on Southeast Asian studies at Peking University, said the word "donation", instead of "compensation", is likely to irritate the Taiwan public as it shows Manila's lack of sincerity.
Amadeo Perez, the special envoy, arrived at Taipei at Wednesday noon. After a 40-minute meeting with Taiwan officials in the evening, Perez extended "heartfelt apology to the family of the fisherman who was shot in the channel between Taiwan and the Philippines".
Perez said he will further discuss issues related to the event with Taiwan's officials on Thursday.
An investigation panel from Taiwan is expected to arrive in Manila on Thursday to join the Philippine National Bureau of Investigation's inquiry, which started on Monday.
Experts said Manila's late and sloppy apology fell short of satisfying Taipei's requests and easing public indignation.
Yang said the Manila-Taipei confrontation from the shooting is getting more complicated as Taiwan leader Ma Ying-jeou, supported by almost unanimous public opinion, is determined not to back down over the incident.