MANILA, Philippines — President Rodrigo Duterte should speak up about what is being called a "hit-and-run" collision near Recto Bank in the West Philippine Sea, Sen. Franklin Drilon said, adding he hopes the Senate will be more vocal on issues in the West Philippine Sea.

In an an interview on Super Radyo dzBB, a transcript of which was provided by Drilon's office, the Senate minority leader said Duterte should say something.

The Palace has condemned the incident and the Department of Foreign Affairs has filed a diplomatic protest but the president—who made the exaggerated claim during the election campaign that he would ride a jetski to the area and plant a Philippine flag in there, has yet to comment on the incident himself.

"Yes (he should speak up), because this involves the sovereignty of the country. It happened in a disputed area. We cannot say this is just a maritime accident or just a matter for maritime law. National sovereignty and national pride are involved," Drilon said in Filipino.

"At the very least, we should ask them for an apology," he said.

The Palace has also attributed the silence from Duterte, known for his off-the-cuff remarks and train-of-thought speeches, to his being a "cautious" man who makes "calibrated responses."

Drilon agreed with the need to "calibrate" the Philippines' response to China, which the government sees as a major source of funding for infrastructure projects, but said that "to assert our sovereignty and point out the indignity they committed against our people is something that we must sustain."

The Philippines has raised the abandonment by the Chinese crew with the International Maritime Organization, saying "it is the obligation of every responsible member-state of the UN and the IMO to implement these conventions and related codes concerning maritime safety and security, rather than just paying lip service to them."

READ: Embassy: It was Chinese ship, but no hit and run

'Multilateral approach better'

As part of its pursuit of better relations with China, the Duterte administration has set up a bilateral mechanism with China to iron out issues in the West Philippine Sea, the part of the South China Sea that the Philippines claims under international law. But Drilon said the bilateral mechanism puts the Philippines at a disadvantage.

China has acknowledged that a China-flagged ship, the Yuemaobinyu 42212, was involved in the incident but has rejected the label of a "hit and run." In a statement, it said the Chinese boat was "suddenly besieged by seven or eight Filipino fishing boats" while fishing, prompting it to leave the area. It said the fishing vessel "failed to shun a Filipino fishing boat" and hit it, causing F/B Gimver 1 to founder.

China said Yuemaobinyu 42212 was afraid if being "beseiged" by the Filipino boats so it sailed away when it was sure the Filipinos were safe.

READ: Palace: Bilateral talks best way to address South China Sea row

"This shows it is not effective. China can ignore us. They have a strong economy and a strong military. That's why we are pushing for a multilateral approach on this. The Philippines is not the only claimant here, many other countries are involved," Drilon said, adding that all those nations should sit down and talk.

Drilon hopeful Congress will do better

Drilon added the 18th Congress, which meets in July, should be more involved in issues in the West Philippine Sea.

"It is sad that this was not given much attention by the Committee on Foreign Relations. As you said, not a lot was heard about this. The next Congress should do better than that," he said, adding he is hopeful that Sen. Aquilino Pimentel III will be more active when he is named chairman of that committee.

"Let's see. If it is Koko (who will chair the committee), his orientation is as a lawyer. These incidents require the rule of law. As a lawyer, Senator Pimental should show that the law should be followed in these things."

The administration PDP-Laban party, of which Pimentel is president, is in an alliance with the Communist Party of China. "This is a free country, we can choose whom we partner with," he said in March 2018 in defense of the partnership.