Washington said on Friday it was lifting a ban on sales of F-16 fighters to Pakistan - imposed in 1990 as a sanction over its nuclear weapons programme - to demonstrate support for a country that has become a major ally in the war on terrorism.
In response, New Delhi on Monday expressed "great disappointment", saying it "could have negative consequences for India's security environment".
After its F-16 offer to Islamabad, Washington tried to sweeten the pill for a neighbour that has fought three wars with Pakistan, signaling its willingness to sell the planes to India too - along with the more advanced F-18 Hornet.
It also said it would consider providing technology for New Delhi's civilian nuclear programme, a sign that Washington is willing to look beyond Pakistan to develop long-term strategic ties with an economically robust and militarily strong India.
"The reasons for which Pakistan is provided with this level of weapons are not much justified," Defence Minister Pranab Mukherjee said on Monday.
"The reason is that it will help Pakistan to fight against terrorism and the Taliban. But this type of equipment is not required to fight against terrorists. This equipment is required for a fully fledged war."
"Therefore, to my mind, supply of these weapons and equipment at this juncture of time will have an adverse impact on the composite dialogue which we are entering into with Pakistan and it may jeopardise the confidence-building measure."
The US has put no limit on the
number of F-16s it would sell
On Sunday, Mukherjee said India would consider buying military equipment from the United States, but had no intention of joining the arms race.
India and Pakistan have been involved in peace talks for over a year aimed at ending more than half a century of hostility, mainly over the Kashmir region, which both claim.
The neighbours will start a bus service next month between their respective sectors of Kashmir, one of the most tangible signs of a fledgling peace in the Himalayan region.
Pakistan President Pervez Musharraf told state television that Pakistan wanted the latest version of the F-16 planes, and the US had put no limit on the number it would sell.
"This will make a strategic difference. For our defence capability and our strategy of defensive deterrence, it will be enhanced," he said.
"The reasons for which Pakistan is provided with this level of weapons are not much justified"
Indian Defence Minister
The US move on the F-16s came after Islamabad said last week it was considering greater cooperation with the UN's International Atomic Energy Agency in its investigation of Iran's nuclear programme.
Diplomats familiar with the UN investigation said this month Pakistan had agreed to hand over centrifuge components so UN inspectors could compare them with machinery sold to Iran by Abd al-Qadir Khan, father of Pakistan's atomic bomb programme.