Metro Manila (CNN Philippines, July 1) — The deal between Philippines and China, which allows Chinese fishermen to operate in the Philippines' exclusive economic zone, is enforceable despite the absence of a written agreement, Presidential Spokesperson Sal Panelo said on Monday.

"Sa palagay ko walang pinirmahan. Nag-usap lang sila. Mga heads of state, may mga word of honor ang mga 'yan, hindi na kailangan," he said in a media briefing.

Panelo, who also serves as the presidential legal counsel, said the deal is legally binding even if it's not formalized in writing.

"Sa batas, kahit verbal, valid at binding 'yun basta may mutual consent ang dalawang partido. Kaya nga agreement," he added.

President Rodrigo Duterte earlier revealed he entered into a deal with Chinese President Xi Jinping that China will no longer block fishermen from Scarborough Shoal — the subject of a standoff in 2012 — in exchange for permit to fish in Recto Bank, also known as Reed Bank.

The fishing rights were agreed upon by the two leaders during Duterte's state visit to China in 2016, but it was only publicized in June following the Recto Bank incident.

Because of the agreement, Duterte argued that enforcing a ban on Chinese fishing in Philippine waters would cause a problem.

“Kung i-prohibit ko, how do I enforce? Takot nga ang Amerika. Ayaw nga mag-confront. Tapos ako pa ang ipusta nila? Gusto talaga nila mapasubo ako,” he said on June 26.

Issues on Philippine sovereign rights over features in the West Philippine Sea arose anew after a Chinese vessel hit a Filipino fishing boat near Recto Bank on June 9, and left the scene as the 22 Filipino fishermen's boat was sinking.

Recto Bank lies 85 nautical miles off the Palawan and the arbitral tribunal recognized it as part of the Philippines' continental shelf.