WASHINGTON: The Obama administration is preparing to sell eight F-16 fighter jets to Pakistan in an attempt to bolster the two countries' relationship despite Washington's reservations about Pakistan's growing nuclear arsenal, said a report published on The New York Times (NYT) website.

The aircraft sales, which the United States (US) Congress could block, would be a symbolic step given Pakistan's current large fleet of fighter jets.

According to the NYT report, the Congress was notified just days ago about the proposed sale of the additional fighters although it is not clear if the White House plans to announce the sale of the aircraft during Prime Minister Nawaz Sharif's ongoing visit to Washington.

Know more: Nawaz arrives in US on four-day visit

The new fighter jets would add to Pakistan’s sizable force of fighter jets which includes more than 70 F-16s and dozens of French and Chinese attack aircraft, the report said.

Earlier in April, the US State Department approved Pakistan’s request for a billion dollars worth of military hardware and equipment, identifying Pakistan as a country of vital importance for US foreign policy and national interests.

In May this year, the US handed over to Pakistan over 14 combat aircraft, 59 military trainer jets and 374 armoured personnel carriers, Dawn newspaper had reported. The weapons supplied to Pakistan were earlier used by American forces in Afghanistan and Iraq.

The NYT report says that many in the US Congress are concerned that the F-16 jets are more useful to Pakistan in its long confrontation with India than for counterterrorism operations.

It is not certain whether the Congress will approve the deal. According to NYT, the Congress and the US State Department are already in a standoff over an effort to sell used Navy cutter vessels to Pakistan earlier this year.

In March, the US House Committee on Foreign Affairs put a hold on about $150 million in foreign military financing. The committee said the cutters were not essential to fighting militants, NYT quoted American officials as saying.

The decision of the sale of fighter jets comes ahead of Thursday's meeting between President Barack Obama and Prime Minister Nawaz Sharif.

Obama is expected to press Nawaz on the Taliban, nuclear safety and a range of other issues when the troubled allies meet at the White House.

Despite efforts to smooth divisions behind handshakes, smiles and items of agreement, long-standing security concerns are likely to dominate the Oval Office discussions.

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Islamabad's alleged ties with the Afghan Taliban, its alleged support for groups opposed to India and the US and its rapidly growing nuclear arsenal are seen by Washington as security headaches.

The US is interested in moving Pakistan toward an arrangement limiting the scope of its nuclear stockpile, but there are few signs that any breakthrough is in sight.

In a new report released Thursday, two authoritative nuclear analysts estimated that Pakistan's nuclear weapons stockpile has increased to between 110 and 130 warheads from an estimated 90 to 110 in 2011.

The analysts, Hans M. Kristensen and Robert S. Norris, foresee it possibly expanding further to 220 to 250 warheads in another 10 years. That would make Pakistan the world's fifth largest nuclear weapons state behind the United States, Russia, China and France.

Also read: Pakistan's nuclear stockpile could become world's third largest, says report

Washington's relationship with Islamabad is a prickly one, born of a fraught inter-dependency but pollinated by mutual mistrust.

Relations were plunged into deep crisis when 9/11 mastermind Osama bin Laden was discovered to be living in the major Pakistani garrison city of Abbottabad.

"The bottom line is that there are a lot of deep disagreements between these two countries," said Michael Kugelman of the Woodrow Wilson Center.

The meeting of Nawaz and Obama comes as the White House increasingly shifts its focus in South Asia to Pakistan's rival India.

Afghan Taliban to table?

But Pakistan remains a key player in the region.

Obama recently announced that US troops would be staying in Afghanistan longer than he had promised, but the White House is keen to get the Afghan Taliban to the negotiating table.

The resurgent Islamists briefly captured the key northern Afghan city of Kunduz this month.

The US sees Pakistan as one of the few sources of influence over the extremists, and analysts say Washington will use the four-day trip to urge Nawaz to keep pushing for a new round of talks. Experts say new Afghan Taliban leader Akhtar Mansour has close ties to Pakistan.

Kabul has accused Islamabad of harbouring and nurturing Afghan Taliban insurgents — allowing them to launch attacks in Afghanistan before melting back across the border.

Obama recently previewed his meeting with Nawaz by saying: "I will continue to urge all parties in the region to press the Taliban to return to peace talks and to do their part in pursuit of the peace that Afghans deserve."

Furthermore, ahead of Nawaz's visit, there have been suggestions that cooperation and a possible deal could be reached on Pakistan's nuclear weapons.

During George W. Bush's presidency a deal was reached with India to normalise nuclear cooperation in return for safeguards.

But US officials have poured cold water on that suggestion.