Former Philippine president Fidel Ramos has cancelled a planned trip to Beijing for what was supposed to be a second round of talks to rebuild tattered ties between his country and China.
An aide to Mr Ramos did not give a reason for the aborted visit, but a source quoted by Reuters said it might have been due to a conflict with President Rodrigo Duterte's schedule this year.
Mr Duterte will fly to Vietnam today, and arrangements are being made for him to visit China and Japan by end-October.
The source said Mr Ramos, 88, would still go to Beijing when the time was right.
Mr Ramos, appointed by Mr Duterte as a "special envoy", is trying to mend Philippine-China relations, frayed by years of tense diplomacy under former president Benigno Aquino over disputes in the South China Sea.
After his visit to Hong Kong last month, he said he had fruitful dialogues with former Chinese deputy foreign minister Fu Ying, who is now chairman of the foreign affairs committee of the National People's Congress, towards bringing Manila and Beijing together for bilateral talks.
Mr Ramos has had to negotiate with his Chinese counterparts amid Mr Duterte's fuzzy foreign policy.
China claims most of the South China Sea. The Philippines, Brunei, Malaysia, Vietnam and Taiwan have rival claims.
In July, an international tribunal ruled that China's claims were invalid. Beijing has refused to recognise the ruling, and insisted it will not enter into talks with the ruling as a starting point.
Mr Duterte has said the tribunal's decision will remain at the heart of bilateral talks with China, but that he will raise it only at the "appropriate time".
He has also signalled concessions meant to bring the Philippines closer to China, as he comes under increasing pressure from the United States over thousands of extrajudicial killings that have marred his anti-crime drive.
He has, for instance, ordered the Philippine Navy to refrain from joining US patrols in the South China Sea. But Mr Duterte has also said the Philippines needs the US, and that he will honour all its treaty obligations and not ask the Americans to leave.
Despite Mr Duterte's bid for warmer ties with Beijing, the Philippines yesterday said Filipino fishermen were still being harassed by China's Coast Guard near a disputed atoll in the South China Sea.
Citing reports from the Philippine Coast Guard, the National Security Council said three Chinese Coast Guard ships descended on a Philippine fishing boat near Scarborough Shoal on Sept 6.
The boat's captain tried to haggle with the Chinese, insisting his men had a right to fish there.
On Sept 10, a boat manned by Philippine Coast Guard "operatives" was also chased away from Scarborough.
A video released on Monday, meanwhile, showed two ships from the Philippine and Chinese Coast Guards sailing dangerously close to each other near Scarborough last Friday.