A top Republican Senator has asked his colleagues in the Senate to join him in opposing the sale of eight nuclear-capable F-16 fighter jets to Pakistan, saying it was "past time" to demand accountability from the country whose "coziness" with terrorists has harmed the US military.

"Selling military hardware to Pakistan -- with a generous subsidy from American taxpayers -- is no way to convince them to become responsible players in the international community and assist in the fight against terrorism," Rand Paul said.

"It is past time to stand up and demand greater accountability from Pakistan -- that it fully severs its ties with terrorist organisations, and that it respect the rights of its own people," Paul said in an official correspondence to other members of the US Senate.

In the letter, Paul urged Senators to join him in blocking the sale of F-16s to Pakistan in an over $600 million deal.

"I request that you support the resolution of disapproval when it comes up for consideration."

Last week, he introduced a resolution in the Senate in this regard. The Senate Joint Resolution 31, if passed by the Senate, would prohibit the sale of F-16s and additional major and non-major defence equipment to Pakistan.

Under the Arms Export Control Act, the joint resolution is privileged. Paul said he would seek vote on the sale of F-16s. "Why should the US consider selling major defence items to Pakistan whose allegiance to the Afghan Taliban and the Haqqani network is well-known," Paul said.

He said just last week Senator Bob Corker, Chairman of the Senate Foreign Relations Committee, criticised Secretary of State John Kerry for advocating a deal that would cost the US taxpayer millions.

Senator John McCain, Chairman of the powerful Armed Services Committee, has also voiced concerns over the sale. House Foreign Affairs Subcommittee on Asia and the Pacific Chairman Matt Salmon said the sale was "extremely problematic in light of the Pakistani military's widely alleged complicity in terrorist violence..."

Representatives Ted Poe and Tulsi Gabbard sent a letter to Kerry on February 16 citing Pakistan's duplicitous nature.

Paul said Pakistan's "coziness with terrorists has harmed our military" and a recent Congressional report authored by the Pentagon cites how Pakistan's support for terrorists allows for IED components to make their way across the border into Afghanistan, targeting US and Afghanistan forces.

General John F Campbell, who till recently was Commander of US and NATO forces in Afghanistan, testified this year before Congress that, "Haqqani Network remains the most capable threat to US and coalition forces, planning and executing the most violent high profile attacks in Kabul."

Paul also said Pakistan's human rights record is abysmal. "Pakistan fails to provide protection for religious minorities such as Shia Muslims, Christians, Ahmadi Muslims and Hindus," Paul added.