KABUL, Afghanistan (AP) - One of the world's testier strategic relationships is deteriorating by the day as Afghanistan accuses Pakistan of meddling in its affairs and prolonging a 14-year war by aiding Taliban militants in a cynical quest for influence.
Pakistan, which hosts masses of Afghan refugees, denies the charge and says it cannot be expected to monitor the movement of Afghan militants back and forth across border regions barely under the control of Islamabad.
This has been a longstanding issue between the two neighbors but a recent uptick in stridency is striking - and dangerous at a time when the Taliban seem to grow more militant and NATO has pulled its combat troops from Afghanistan.
It also represents a reversal of the relatively optimistic outreach Afghan President Ashraf Ghani launched when he took office a year ago.
The relentless continuation of Taliban attacks - and the surge in violence that followed the transfer of security control from NATO to Afghan forces at the end of 2014 - seems to have exhausted Ghani's patience.
After a series of deadly attacks earlier this month in the Afghan capital, Ghani accused Pakistan on live TV of being the source of the violence in his country.
"The decisions the Pakistani government will be making in the next few weeks will significantly affect bilateral relations for the next decades," Ghani said at the time. "We can no longer tolerate watching our people bleeding in a war exported and imposed on us from outside."
Amid the rhetoric, the basic facts are not in dispute: leaders of the Taliban have been based in Pakistan - in Quetta, Peshawar and Karachi - since the U.S.-led invasion in 2001 toppled their regime and forced them to flee.
Recent events also have made clear the extent of Pakistan's influence over the group. Taliban leaders direct the war from Pakistani soil, and send gunmen and suicide bombers, weapons and money across the border every year for the Taliban summer offensive. This year, the warm-weather offensive has been particularly ferocious, following the NATO drawdown.
On Tuesday, Pakistan's ambassador to Kabul, Syed Abrar Hussain, was summoned to hear a complaint about border shelling, Afghan Foreign Ministry spokesman Ahmad Shekib Mostaghni confirmed.
A day later - on Afghan Independence Day - Afghan Ambassador Janan Mosazai was summoned by Pakistan's foreign ministry, where he heard a protest about a "recent spate of Afghan government's allegations and media campaign to malign Pakistan," a ministry statement said.
The "allegations undercut mutual confidence and affect the environment of bilateral relations that both countries had been working hard to improve," said Pakistan's foreign secretary, Aizaz Ahmad Chaudry.
Earlier, Ghani had told Kabul-based ambassadors Pakistan "has three options: freeze, deep freeze or hostility" if it failed to reign in the Taliban, according to three people who were present at the meeting, including two ambassadors. All spoke on condition of anonymity because they were not authorized to talk to the media.
"We are at "freeze,'" said one of the ambassadors. "Relations could still go down - for instance, if there is a new bombing in Kabul."
The diplomat said unless the Pakistanis "deliver what they are saying they are willing to do, to combat terrorism and extremism," Afghanistan's allies could ask the United States and the world to classify Pakistan as a provider of "sanctuary to terrorists."
Such a classification could lead to diplomatic and financial isolation for Pakistan and complicate its relationship with other partners, like China, as well as global lenders and credit rating agencies.