The Pakistani prime minister, Nawaz Sharif, has met John Kerry, US secretary of state, in Washington in advance of talks in the White House aimed at improving an uneasy relationship with the US administration.
Kerry said on Sunday the US relationship with Pakistan "could not be more important", underscoring the South Asian country's economic and security woes in the context of regional stability.
Kerry, who visited Islamabad in August, called Pakistan a "democracy that is working hard to get its economy moving and deal with insurgency and also important to the regional stability".
The State Department said the pair discussed counterterrorism cooperation, energy, trade and investment, and "the common interest in a secure and stable Afghanistan".
Sharif, who is due to meet President Barack Obama on Wednesday, did not speak during Sunday's brief session with reporters.
US officials have said the Obama administration is poised to release more than $1.6bn in military and economic aid to Pakistan.
Aid release expected
For a start, the State Department has asked Congress to resume more than $300m in blocked security assistance to Pakistan, officials said on Sunday.
"This is part of a long process of restarting security assistance cooperation after implementation was slowed during the bilateral challenges of 2011 and 2012," Marie Harf, deputy State Department spokeswoman, said.
"Both sides agreed on the importance of our continued counterterrorism cooperation, and that extremism is countered in part by opportunities arising from greater economic stability," the State Department said.
Sharif was elected in May, and the US has praised his efforts to reduce tensions in South Asia.
Relations with the US have also improved since they plunged to one of their lowest points in 2011 after US commandos killed Osama bin Laden, al-Qaeda's leader, in a raid in Pakistan and a US air raid left 24 Pakistani soldiers dead.
US security assistance was interrupted during that period, although $857m in civilian assistance continued to flow, Harf said.
"As part of our annual funding process, throughout the course of this past summer the State Department notified Congress of how it planned to programme funds from several different accounts for various programmes in Pakistan," she said.
The US needs Pakistan's cooperation as it prepares to withdraw thousands of pieces of heavy equipment from Afghanistan before NATO combat operations end in late 2014.
It is also looking to Pakistan to try to help with reconciliation efforts between the Taliban and Afghan leaders.
"Funding was notified to Congress following a rigorous planning process over multiple months, to ensure it was in line with both US and Pakistani interests, and would deliver important results for both countries," the State Department's Harf said.
She said US security assistance would build the capabilities of Pakistan's security forces, "which is critical to countering violence in the western border regions.
"And US civilian assistance to Pakistan has delivered real results on the issues most important to Prime Minister Sharif and all Pakistanis: energy, education and economic growth".