(UPDATED) Permanent Representative to the United Nations Teddy Boy Locsin, Jr. early Friday said he accepted his appointment as the next Department of Foreign Affairs (DFA) secretary.

Locsin will replace Alan Peter Cayetano, who will run as congressman of Taguig in the 2019 polls.

Cayetano aims to replace his older sister Taguig 2nd District Rep. Pia Cayetano, who seeks a Senate comeback.

Locsin said he "trusts (President Rodrigo Duterte) completely."

"I was asked I said yes; but love UN, the many friends & intellectual companions I made. But I didn’t say no when asked as I didn’t when he told me I was UN ambassador. If my Tito Chito Ayala trusted him implicitly; how can I not. Still UN work is like sharpening a blade every day," he told ABS-CBN News on Twitter.

I was asked I said yes; but love UN, the many friends & intellectual companions I made. But I didn’t say no when asked as I didn’t when he told me I was UN ambassador. If my Tito Chito Ayala trusted him implicitly; how can I not. Still UN work is like sharpening a blade every day https://t.co/Zc0SHbtpE4

— Teddy Locsin Jr. (@teddyboylocsin) October 11, 2018

"I will be Secretary of Foreign Affairs which includes the UN; I will have a direct hand until the architecture of sovereign independence in all matters of state that my team started to erect is remitted. Talent that doesn’t exist outside DFA will complete it," he added.

I will be Secretary of Foreign Affairs which includes the UN; I will have a direct hand until the architecture of sovereign independence in all matters of state that my team started to erect is remitted. Talent that doesn’t exist outside DFA will complete it.

— Teddy Locsin Jr. (@teddyboylocsin) October 11, 2018

ABS-CBN News sources earlier disclosed that Duterte may tap Locsin to replace Cayetano, who sought permission to run in next year's elections.

Prior to becoming an ambassador, Locsin was an ABS-CBN journalist, lawmaker, and newspaper publisher.

He served as Makati representative from 2001 to 2010.

Locsin was also speechwriter and press secretary of then President Corazon Aquino after the People Power Revolution against the Marcos dictatorship.

Duterte appointed Locsin as Philippine envoy to UN in 2016.

• READ: Teddy Locsin Jr. is new envoy to UN

Asked on who who will be the next Foreign Affairs secretary, Duterte told reporters Friday said the public should ask Locsin.

"I don’t know, baka ayaw niya i-announce, I don’t have his permission. Mahirap kasi if I give out his name tapos tatanggapin niya. Bong (Go), tawagan mo nga si Teddy Boy Locsin, sabihin mo kung [pwede] i-mention pangalan niya dito?" Duterte told reporters in Davao City.

"I don’t know. Okay na? Okay na sabi niya, there’s a more powerful guy. Next time don’t ask me questions, you ask him,” pointing to Special Assistant to the President Bong Go.

• READ: Duterte on next DFA secretary: Ask Teddy Boy Locsin