THE US State Department on Tuesday called on the government of President Ferdinand R. Marcos, Jr. to step up efforts to resolve politically motivated lawsuits against civic leaders after former Senator Leila M. de Lima’s acquittal from in her last drug trafficking case.

“We continue to urge the Philippines to resolve politically motivated cases including those against journalists and civil society, in a manner consistent with its international human rights obligations and commitments,” Department of State spokesman Matthew Miller said in a statement posted on the agency’s website.

A Muntinlupa court on Monday acquitted the former lawmaker, who had been in jail for nearly seven years, in her third and last drug trafficking case that she said was fabricated to muzzle her investigation of then-President Rodrigo R. Duterte’s deadly war on drugs.

Presiding Judge Gener M. Gito said prosecutors failed to prove that Ms. De Lima had been involved in the illegal drug trade. The same court granted her bail plea in November.

She was accused of promoting the illegal drug trade inside the national penitentiary in Muntinlupa during her time as Justice secretary. 

Convicts allegedly bribed her with P70 million, which she allegedly used to fund her senatorial campaign.

“The United States remains committed to working with the Philippines to strengthen democracy and human rights around the world,” the US agency said.

Ms. De Lima incurred Mr. Duterte’s ire when, as chairwoman of the Commission on Human Rights, she started a probe in 2009 into extrajudicial killings by the so-called Davao Death Squad in the tough-talking leader’s hometown, where he was the long-time mayor. Mr. Duterte later vowed to “destroy” her.

Amnesty International has said the government had deprived the ex-senator of her right to a fair trial through her arbitrary detention.

Political experts have said her detention showed how the government had abused the justice system.

The government estimates that at least 6,117 suspected drug dealers were killed in police operations. Human rights groups say as many as 30,000 suspects died.

Meanwhile, militant group Bayan Muna urged Ms. De Lima to campaign for the release of other political prisoners charged under Mr. Duterte’s government.

Her voice would be influential in calling for the government to release other political prisoners, Bayan Muna Executive Vice President Carlos Isagani T. Zarate said in a statement.

“With the junking of all her drug cases, we appeal to Senator Leila de Lima to actively campaign for the release of all other political prisoners, especially those persecuted by Duterte,” he said.

There are about 800 political prisoners in the Philippines, according to human rights groups.

Ms. De Lima’s detention showed how Mr. Duterte manipulated state institutions to persecute those critical of his government, Mr. Zarate said. “Democratic institutions were weaponized to suppress dissent and criticism.”

“The bastardization of the country’s justice system needs to be urgently addressed to prevent a repeat of its miscarriage as in the case of Ms. De Lima and those similarly situated,” Mr. Zarate said.

He said the misuse and abuse of legal and judicial processes for political gain undermined the country’s rule of law during Mr. Duterte’s rule. — John Victor D. Ordoñez and Kenneth Christiane L. Basilio