United States (US) President Donald Trump on Monday began his new year by accusing Pakistan of giving Washington "nothing but lies and deceit".
The US president also tweeted that Islamabad thinks of US leaders "as fools".
He said Washington had "foolishly given Pakistan more than $33 billion in aid over the last 15 years", but Pakistan had in return given "safe haven to the terrorists we hunt in Afghanistan, with little help".
"No more," he added, without specifying what punitive actions — if any — his administration is considering.
The American president's tirade was responded to briefly by Foreign Minister Khawaja Asif, who said Pakistan would "soon" show the world the "difference between facts and fiction."
Later in the day, the Foreign Office summoned the American ambassador in Islamabad, David Hale, to record its protest against the accusatory statement tweeted by Trump, DawnNews quoted a senior FO official as saying.
US Embassy Spokesman Rick Sinelsine confirmed the development, saying Ambassador Hale had been called for a meeting at the Foreign Office at 9pm.
Sinelsine, however, said that he was unaware of the agenda of the meeting.
Meanwhile, Prime Minister Shahid Khaqan Abbasi convened a meeting of the National Security Committee to review the national and regional security situation.
According to Radio Pakistan, the meeting will be attended by the ministers of Interior, Defence and Foreign Affairs, the services chiefs, and other civil and military officers.
Moreover, the federal cabinet was also expected to meet in Islamabad on Tuesday with the prime minister in the chair to discuss recent developments.
The US president's tweet came in the aftermath of an increasingly terse back-and-forth between Washington and Islamabad since Trump announced his administration's latest national security strategy.
During the announcement, the US president had been quick to remind Pakistan of its 'obligation' to help America "because it receives massive payments" from Washington every year.
"We have made clear to Pakistan that while we desire continued partnership, we must see decisive action against terrorist groups operating on their territory. And we make massive payments every year to Pakistan. They have to help," the US president had said.
A Pentagon report to the US Congress, released to the media on Dec 17, had said Washington would also take 'unilateral steps' in areas of divergence with Pakistan while expanding cooperation between the two countries where their interests converge.
Subsequently, US Vice President Mike Pence had, in a surprise visit to Afghanistan's Bagram airbase on Dec 22, warned that Trump has "put Pakistan on notice" in what was the harshest US warning to Islamabad since the beginning of the Afghan war over 16 years ago.
Official sources had told Dawn last week that the Trump administration was also considering withholding $255 million from a fund meant to provide military training and equipment to Pakistan, adding to already existing cuts on reimbursements.
The Pakistan Army spokesman, Maj Gen Asif Ghafoor, had at a press conference last week asserted that the aid Pakistan received from the US was "reimbursement for support we gave to the coalition for its fight against Al Qaeda."
"Had we not supported the US and Afghanistan, they would never have been able to defeat Al Qaeda," he had said.
"The armed forces are working with friends and want to continue doing so, but there can be no compromise on our national honour. We do not want a conflict with our friends, but will ensure the security of Pakistan," he had added.
His briefing was considered perhaps the strongest-ever reaction from Islamabad since US functionaries began alluding to the possibility of unilateral action.
Hitting back at the US, the civilian-controlled Foreign Office (FO) had also warned against the "malicious campaign" being "used to trivialise Pakistan's achievements in the war against terrorism", and noted that "allies do not put each other on notice."
The FO had further complained that recent US statements are "at variance with the extensive conversations we [Islamabad] have had with the US administration".
— With additional reporting by Naveed Siddiqui in Islamabad.