ISLAMABAD, Pakistan — Tensions between Pakistan and Afghanistan over potential Taliban peace talks spilled into the open on Friday, with Pakistan’s foreign minister saying it was “preposterous” for Afghanistan to demand that her country deliver the insurgent leadership to the negotiating table.

“If that is the expectation, there is no reality check,” said the foreign minister, Hina Rabbani Khar. “It is not only unrealistic, but preposterous.”

Ms. Khar was speaking at the conclusion of a two-day trilateral meeting among the leaders of Iran, Afghanistan and Pakistan in Islamabad, Pakistan, that was supposed to focus on regional cooperation but was overshadowed by a tentative American-driven initiative to start peace talks with the Afghan Taliban.

Her comments are significant because the Taliban leadership — and many of its fighters — are believed to be hiding in Pakistan or using Pakistan’s tribal areas as a base to attack Western and Afghan forces.