Pakistan Foreign Minister Shah Mahmood Qureshi, who heads the Pakistani delegation of senior cabinet officials, and Army chief Gen. Ashfaq Kayani led a delegation that arrived here Sunday. The Pakistanis have come wanting an improvement of bilateral relations through such aid as civilian nuclear assistance and military equipment aimed at balancing its power with India.

A senior Pakistani official told CBS News the meetings represent “the most important event in years” for relations between the two nations linked by the war against Islamic extremists.

The meetings, which began here Wednesday, will be the fourth round of discussions between the two countries since 2006 and the first that will include direct involvement of top-ranking government officials from both sides.

Other members of the Pakistani delegation include Lt. Gen. Shuja Pasha, head of Pakistan’s Inter-Services Intelligence and Defense Minister Ahmed Mukhtar.

Kayani arrived Sunday at Central Command headquarters in Tampa for meetings with Gen. David H. Petraeus, and held separate meetings here Monday and Tuesday with Secretary of Defense Robert Gates and Chairman of the Joint Chiefs of Staff Gen. Mike Mullen.

Other key members of the US delegation include leaders from the trade, agricultural and economic sectors.

Pakistan recently stepped up its efforts to eradicate terrorist factions within its own borders through an aggressive pursuit of militants, arresting Afghan Taleban members and even apprehending top Taliban commander, Mullah Abdul Ghani Baradar.

Meeting with the delegation on Wednesday, US Secretary of State Hillary Clinton said the US wanted a new relationship with Pakistan but was realistic of the challenges ahead in reversing decades of mistrust.

“It is the start of something new,” Clinton said. “Our countries have had our misunderstandings and disagreements in the past and there are sure to be more disagreements in the future.”

“The US and Pakistan have always come together in critical times,” she said, adding that the next round of strategic dialogue will be in Islamabad.

Speaking alongside Clinton, Qureshi pledged support for action against extremism but also said that Pakistan had key wishes from the United States.

“We hope non-discriminatory access to vital energy resources will also be made available to us so that we too can pursue our economic and industrial development plans,” he said.

He also called for a “constructive” US role on Kashmir.

Pakistani officials also want to jump-start the $7.5-billion aid package recently approved by the US Congress and scheduled to be delivered to Pakistan over the next five years.

This is expected to produce several agreements, from building dams and roads to power projects for energy-starved Pakistan, as well as additional security commitments and continued economic and political reform.

In addition to the $7.5 billion in aid, the US has recently provided Pakistan with 1,000 kits for manufacturing laser-accurate explosive projectile weapons. These are designed to give the Pakistani Air Force an upper hand in battles against insurgency.

Among the more contentious issues is Pakistan’s quest for US cooperation on a civil nuclear reactor. Pakistani leaders say this would go a long way in helping the country deal with its current power shortage. This agreement would be similar to one granted by Washington India under the administration of President George W. Bush.

Continued fears over Pakistan’s proliferation record remain a major stumbling block. In particular, US officials want to question A.Q. Khan, the disgraced former head of Pakistan’s nuclear program who admitted to being involved in the transfer of nuclear technology to countries such as Iran and North Korea.