"We have cautioned the US against such a decision," Singh told parliament just hours before US Defence Secretary Donald Rumsfeld was due to arrive for talks with the Indian leadership.

"We have also conveyed that US arms supply to Pakistan would have a negative impact on the goodwill the United States enjoys in India, particularly as a sister democracy," he added.

Pakistani President Pervez Musharraf met US President George Bush last Saturday during which he said he discussed the potential purchase of the F-16 fighters.

Nuclear-armed India and Pakistan have fought three major wars and one snap border flare up in 2002 and any major arms deal by either country is seen as a threat by the other.

The two rivals are engaged in peace talks to resolve several disputes including the core problem of Kashmir.

Singh said New Delhi has pointed out that the supply of arms to Pakistan by the United States at a time when the dialogue between the two countries is at a "sensitive stage" would have a "negative impact".

Pakistan reportedly wants to buy up to 25 of the F-16s, which cost around 25 million dollars each, by mid-2005 to add another squadron of such planes to its existing fleet.

Musharraf has won Bush's firm support since he sided with Washington to oust Afghanistan's Taliban rulers, originally backed by Pakistan, after the September 11, 2001 attacks.

Singh termed India's relations with Pakistan as "accident-prone".

"We have therefore to deal with this matter with great restraint, great wisdom (and) patience," he said.

The minister, who was India's high commissioner (ambassador) to Pakistan during the mid-eighties, said that of late relations had improved.

"... I must say that the atmosphere between the two countries has considerably improved and it is our endeavour that it remains so. There are complicated issues going back many decades. There are no quick fixes, no magic solutions available. All we can do is try," Singh said at the end of a two-day debate on foreign policy.