Pakistan has summoned the US ambassador, an embassy spokesman said Tuesday, a rare public rebuke after Donald Trump lashed out at Islamabad with threats to cut aid over "lies" about militancy.
Ambassador David Hale was asked to go to the foreign office in the Pakistani capital on Monday night, after Islamabad responded angrily to the US President's allegations that it provided safe havens for militants in the latest spat to rock their alliance.
A US embassy spokesman confirmed Hale met officials, but added: "We don't have any comment on the substance of the meeting."
There was no immediate response from foreign office officials.
Trump used his first tweet of 2018 to tear into Islamabad.
"The United States has foolishly given Pakistan more than 33 billion dollars in aid over the last 15 years, and they have given us nothing but lies & deceit, thinking of our leaders as fools," Trump said in the early-morning New Year's Day tweet.
"They give safe haven to the terrorists we hunt in Afghanistan, with little help. No more!"
Pakistan hit back swiftly, saying it had done much for the United States, helping it to "decimate" Al-Qaeda, while getting only "invective & mistrust" in return in angry comments from its foreign and defence ministers.
Islamabad has repeatedly denied the accusations of turning a blind eye to militancy, lambasting the United States for ignoring the thousands who have been killed on its soil and the billions spent fighting extremists.
After the September 11, 2001 terror attacks in the United States, Washington forged a strategic alliance with Islamabad to help in its fight against militancy.
But US leaders have often complained that Pakistan has done too little to help.
Washington and Kabul have long accused Islamabad of supporting militant groups including the Taliban, believed to have links to Pakistan's shadowy military establishment who aim to use them as a regional bulwark against arch-nemesis India.
Of foremost concern in the US is Islamabad's attitude toward the powerful Haqqani network, whose leader Sirajuddin Haqqani is the deputy leader of the Afghan Taliban.
The group is accused of some of the most lethal attacks on US forces in Afghanistan, and was dubbed by America's former top military officer Mike Mullen as a "veritable arm" of Pakistani intelligence.
For many years it found safe haven in Pakistan's semi-autonomous northwestern tribal areas.
However the Pakistani military launched an operation there in 2014, and now insists it has eradicated all safe havens in the country.
US-Pakistani ties, long contentious, have taken a nosedive under Trump, who first signaled that Washington was reassessing the fractious relationship in August, when he accused Islamabad of harbouring "agents of chaos".
The remarks triggered a series of high-level diplomatic meetings in the US and Pakistan, but Islamabad has given few signs of concessions.
The Trump administration told Congress in August it was weighing whether to withhold $255 million in earmarked aid to Islamabad over its failure to crack down more effectively on terror groups in Pakistan.
Pakistani analyst Imtiaz Gul said Trump's latest remarks had evoked a "very harsh" response from Pakistan.
"It will only add to the acrimony that has crept into the bilateral relationship after Trump's arrival in the White House," he told AFP, describing Washington's approach as "more bullying than rational".
He also noted that the assumption in Pakistan is that India is fuelling Trump's hostility towards Islamabad.
India has long vied with fellow nuclear power Pakistan for influence in Afghanistan, building dams, roads and a new parliament in the troubled country, offering millions in aid and training security forces.
Trump and other administration officials have called on India to become more involved in Afghanistan, an idea that is anathema to Islamabad.
"Now Pakistan's first attempt will be to neutralise India's narrative of Pakistan," Gul said.