Pakistan's interior minister on June 12 said the government was ready to throw out more foreign aid groups, one day after expelling Save The Children.
"Many [nongovernmental organizations] are working against Pakistan and we are deliberating on exposing them in the parliament," Chaudhry Nisar Ali Khan told reporters in Islamabad.
NGOs "working against the country's national interest will not be allowed to continue their work in Pakistan," he said.
Pakistan deregistered 3,000 local aid groups in December 2014, according to CIVICUS, a global alliance of civil society organisations.
A draft bill in parliament, the Foreign Contributions Regulation Act 2015, would make it easier for officials to prevent groups that receive foreign funds from operating in Pakistan.
Khan said charities doing "positive" work should not worry, but he singled out activists working for the abolition of the death penalty and judicial reform for criticism.
"We know which local NGOs are involved in this slander campaign," he said. "This propaganda should stop. There should be respect for our judicial system."
In Washington, the U.S. State Department issued a rare rebuke to Pakistan for its increasingly adversarial stance toward humanitarian groups, and suggested it would be harder to channel foreign aid to the country.
"We are concerned about Pakistan's crackdown on international charitable organizations and other NGOs," State Department spokesman John Kirby said, noting the "increasing difficulty of doing business in Pakistan."
"This has had a significant negative impact on international partner efforts to support government of Pakistan priorities," he said.
Aid groups have complained in recent years that increasing government restrictions on their activities have hampered their efforts to help vulnerable people in a country which still has huge numbers who live in poverty.
Work in so-called "sensitive" areas such as southwestern Baluchistan -- the country's poorest, least-developed province -- has been particularly difficult, they say.
Without naming any organizations, Khan said some NGOs had been operating without proper regulation and had worked in Baluchistan when they had permission only to work in Islamabad.
Pakistan will tighten oversight of such groups "working without any rules," he said.
Khan said some groups are using their work as a cover for espionage -- an accusation Pakistan used to justify its action against Save The Children.
"For several years, intelligence reports were being received but no action was taken," Khan said.