High-level U.S.-Pakistan visits were unfolding Wednesday for the first time since Washington announced it was cutting more than one-third of its military aid to its terrorism-fighting partner.

Marine Gen. James Mattis, the head of U.S. Central Command, met with Pakistan's army chief, Gen. Ashfaq Parvez Kayani, and the joint chiefs chairman, Gen. Gen. Khalid Shameem Wynne, the U.S. Embassy in Islamabad said.

Pakistan said the head of its Inter-Services Intelligence agency, Lt. Gen. Ahmed Shuja Pasha, was headed to the U.S. for two days of talks.

With tensions between the two countries already high, the Obama administration said Sunday it was suspending $800 million in aid to Pakistan, signaling a tougher stance toward what it considers a critical but sometimes unreliable ally.

The visit by Mattis was to "share perspectives on the current relationship between the two militaries and to review the way ahead," according to an embassy statement. It said the stop was part of Mattis' routine of consulting with Pakistani officials.

Officials said the trip was planned for some time and was his fifth since becoming U.S. commander for the region 11 months ago.

The Pentagon played down the recent unsettling developments between the two nations and said the relationship will move forward.

"We have ups and downs, not only in this relationship _ with relationships we have with allies all over the world," said Defense Department spokesman Marine Col. Dave Lapan.

"We work through them, that's the purpose of having military-to-military engagements," Lapan told Pentagon reporters, adding that he envisions relations "improving over time."

Despite billions of dollars in American aid since the attacks on Sept. 11, 2001, the U.S.-Pakistan relationship has long been an uneasy one because of Pakistan's reluctance to target Taliban militants on its territory who stage cross-border attacks against NATO troops in Afghanistan.

The relationship soured May 2 when U.S. commandos staged a covert raid to kill al-Qaida chief Osama bin Laden in a Pakistani garrison town not far from Islamabad. The raid humiliated the Pakistani military, which ordered U.S. trainers out of the country and reduced bilateral cooperation.

The Pentagon says the cut in aid includes equipment the trainers took with them when they left, as well as $300 million intended to reimburse Pakistan for its counterterrorism help.

The U.S. had 150 to 200 special operations trainers working with a variety of Pakistani forces, teaching counterinsurgency techniques and sniper skills.

U.S. officials claim that Pakistan has not lived up to pledges to uproot and disrupt Taliban militants and suspected al-Qaida factions in the border region.

President Barack Obama's chief of staff, William Daley, said Sunday that the U.S. was suspending the aid until the two countries can patch up their relationship.

Pasha, Pakistan's spy chief, was expected to meet with the CIA's acting director, Michael Morell. He's running the agency until Army Gen. David Petraeus completes his assignment as the top commander in Afghanistan.

Pasha has pushed for a stop to U.S. drone strikes against militants in Pakistan's tribal areas, unless the targets are agreed upon in advance and Pakistan is informed, Pakistani officials said. U.S. officials say they have no intention of changing their current policy. All the officials spoke on condition of anonymity to discuss sensitive strategic discussions.

Pakistan also wants the U.S. to vacate Shamsi Air Base, in the province of Baluchistan. From there, the U.S. has launched armed drones and observation craft to keep the pressure on Taliban and al-Qaida in Pakistan's tribal areas.

Also expected to be raised in the meetings in Islamabad and Washington is the beating death last month of Pakistani journalist Saleem Shahzad.

Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, said last week that Pakistan's government "sanctioned" the killing, but he said he could not tie the death to the intelligence service.

Two senior U.S. officials have confirmed to The Associated Press that the U.S. government received intelligence indicating that Pakistan's military and intelligence service authorized Shahzad's torture and murder. Pakistani officials have denied involvement in his death.

Shahzad wasn investigating alleged Pakistani military and intelligence involvement in an attack on a Pakistani naval base, where a small number of U.S. personnel were stationed, one U.S. official said. The U.S. personnel were able to escape before the gunmen closed in.