WAShington - Days after the Pentagon announced it is withholding $50 million intended for Pakistan as part of its Coalition Support Fund, the South Asian country's ambassador hinted at potential retaliation, possibly coaxing Washington to negotiate access to the country's air corridors, which Islamabad suggests have been taken for granted, reported Voice of America (VoA) on Saturday.

Pakistan is ready to cooperate with the United States, Ambassador Aizaz Ahmad Chaudhry said, though Washington may now end up having to negotiate with Islamabad on the corridors and other tangible assets, he added.

"All that Pakistan has done in the fight against terrorism has not been sufficiently factored" into the US decision to reduce its support funds, Chaudhry lamented during a discussion this week at the Washington office of the London-based International Institute for Strategic Studies.

Pakistan has facilitated air and ground logistical support for US troops in Afghanistan "like no one else", Chaudhry said, adding that "since 2001, all air corridors from Pakistan have been available to the United States free of cost."

The reason Pakistan did so "was because we believed this was a common war," the ambassador said, but there have been occasions when US actions have left his country's leaders thinking "that perhaps we are not partners."

Questions concerning Pakistan's commitment to bilateral partnership have also been raised by the US. A prime example was the discovery in 2011 that Al-Qaeda leader Osama Bin Laden had been living undisturbed near a key military facility.

US Secretary of Defence James Mattis said he withheld $50 million in Coalition Support Funds because he couldn't certify to Congress that Pakistan had taken sufficient action against the Haqqani network, a Taliban-associated organisation which the US has deemed a foreign terrorist Organisation, since September 2012. The group has been blamed for attacks in Afghanistan.

For its part, Islamabad's message is don't drop "every security lapse in Afghanistan on Pakistan's doorsteps," as the country's ambassador to the US put it.

The Pakistani envoy's remarks came at a time when US President Donald Trump's administration has been reviewing its overall strategy toward South Asia, including India, Pakistan, Afghanistan and Iran. And his defiant tone may reflect Pakistan's decreasing dependence on the United States amid an influx of Chinese capital investments and a strengthening political relationship between Islamabad and Beijing.

Chaudhry indicated in an interview with VoA that Islamabad had grown accustomed to having to negotiate with Washington. "These and all other issues are always negotiated, because that's in the nature of the business" between allies, he said. By contrast, he pointed to Pakistan's "unique" relationship with China, the top strategic rival to the US in Asia.

Islamabad sees Beijing as its closest ally, he added, and the two countries find themselves completely attuned. There is "so much of a meeting of minds," he noted — with no "policy differences at all" dividing them.

Chaudhry told VOA "the clearest example and manifestation" of Sino-Pakistan ties has come in the form of the China-Pakistan Economic Corridor, or CPEC, stretching 3,000 kilometres from Kashgar in western China's Xinjiang region to the port city of Gwadar on the edge of the Arabian Sea.

Due to the strategic importance China attaches to Gwadar and its financial resources, Beijing agreed to build the port for free. China has publicly justified its investment in Gwadar as an alternate route for oil and other commodities headed for the Chinese mainland, but the port's potential for military uses has even more significance for strategic thinkers.

Earlier this year, Pakistan announced it has leased operation rights for Gwadar to a Chinese company for 40 years.

Andrew Small, a senior fellow at the German Marshall Fund of the United States (GMF), said the formal terms are understood to be purely economic in nature. However, "that doesn't preclude its being developed for military purposes further down the line, and both sides certainly have that in mind," he added.

Small is author of The China-Pakistan Axis: Asia's New Geopolitics.

"As its need grows for friends who can facilitate the extension of its reach as a global military power," China is now trying to turn its relationship with Pakistan into a model for other potential security partnerships, Small said.

The question before the United States as it debates its future approach toward Pakistan, in the context of its overall South Asian strategy review, Small said, "is still whether a coherent long-term framework for the relationship can be established, rather than continuing to be dependent on cycles of near-term goals."

"For various reasons, Pakistan still values a good relationship with Washington," the analyst said.

The challenge for Pakistan today, analysts said, is whether the country can seize its current opportunities and rise above a past laden with border disputes and domestic instability, so it potentially can be seen as "an emerging market, even a future rising power," in Small's words.

"Over time, Pakistan would be better off charting its own course toward better relations with its neighbours, and lessening its dependence on both the United States and China," said Ambassador Robin Raphel, a former assistant secretary of state for South Asia.

For now, however, Pakistan's Ambassador Chaudhry told VoA: "Both the United States and China have a global role to play, and Pakistan is a friend of both."

In his view, the ultimate consideration for Pakistan's cooperation with China on Gwadar and CPEC, their economic corridor, comes down to the question of "economic empowerment of the people living in Balochistan and the rest of Pakistan."