PRESIDENT RODRIGO R. Duterte has ordered government lawyers to expand their study of a plan to end an agreement with the US on the deployment of troops and equipment for war games, Justice Secretary Menardo I. Guevarra said on Monday.

In a group mobile-phone message, Mr. Guevarra said the agency would assess the usefulness of the visiting forces agreement and its impact before recommending its termination.

President Duterte last week asked the US government to reverse its decision to cancel Senator Ronald M. dela Rosa’s US visa, giving it a month-long ultimatum.

Mr. dela Rosa, a political ally, last week said the US embassy had canceled his visa. Mr. Duterte’s former police chief led the government’s deadly war on drugs that has killed thousands before he became a senator.

He was also considered to be among those responsible for the detention of Senator Leila M. de Lima, a staunch critic of Mr. Duterte’s anti-illegal drug campaign.

The Justice department was initially tasked to study the procedure in ending the military deal with the US.

Mr. Guevarra said they would study the impact of terminating the VFA on foreign relations, on an enhanced defense cooperation agreement with the US and the Mutual Defense Treaty between the two countries.

A Cabinet cluster made up of the Justice, Defense and Foreign Affairs departments, Armed Forces, and National Bureau of Investigation would assess the deal, he said.

The Senate foreign relations committee earlier said it would study the planned termination.

The chamber would summon officials from the Foreign Affairs and Defense departments to shed light on the status of the VFA, Senator Aquilino L. Pimentel III told dzBB radio on Sunday.

Among other things, the deal allows the US government to retain jurisdiction over American soldiers accused of committing crimes in the Philippines, unless the crimes are “of particular importance” to the Southeast Asian nation.

Meanwhile, Senate President Vicente C. Sotto III also said the Senate’s position on the VFA would probably not influence the Executive decision. “It won’t have a bearing, it will just be a statement,” he said at a briefing.

He also said Mr. Duterte’s threat to end the VFA goes beyond the cancelation of Mr. dela Rosa’s visa. He said it might have been triggered by a US Senate resolution urging the Philippines to release Ms. de Lima.

The US Senate last year passed a resolution asking the Philippine government to release Ms. de Lima. It also sought to block the entry and freeze the US assets of officials behind drug-related killings and Ms. de Lima’s “wrongful detention.”

US President Donald Trump also signed into law last year the nation’s 2020 budget, which includes a clause allowing the US secretary of state to ban the entry of Philippine officials behind Ms. de Lima’s detention.

Ms. de Lima, a staunch critic of Mr. Duterte’s war on drugs, has been in jail since February 2017 for drug trafficking. — Vann Marlo M. Villegas and Charmaine A. Tadalan

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