Indian troops keep a close eye on the border in Rajasthan
The United States has urged India and Pakistan to avoid unnecessarily raising tension amid reports of troop movements to the border.
Pakistan has redeployed some troops from the north-west and some leave has been cancelled, army officials said.
India earlier advised its citizens against travelling to Pakistan amid the continuing tension in the wake of last month's deadly attacks in Mumbai.
The attacks on several targets in the city left more than 170 people dead.
A Pakistani military spokesman called its movements a minimum defensive measure.
And a senior security official said a limited number of soldiers had been pulled out from non-essential positions on the Afghan border and areas where there were no military operations.
Pakistan is suspending some army operations against militants
Pakistani media reported that troops were strengthening some positions on the border with India.
The Line of Control in divided Kashmir and the towns of Kasur and Sialkot were areas mentioned in the reports.
Air strikes against militants in the restive Swat and Bajaur regions had been scaled down as some of the airpower had to be redeployed to the country's eastern border, a senior Pakistani military official told Asif Farooqi, the Islamabad-based correspondent of the BBC Urdu service.
There have been reports of possible forthcoming "surgical" strikes by India on the headquarters and camps of Lashkar-e-Taiba, the militant group India blames for the Mumbai attacks.
The group and Pakistan's government deny any involvement.
White House spokesman Gordon Johndroe said: "We hope that both sides will avoid taking steps that will unnecessarily raise tensions during these already tense times."
He said the US remained "in close contact with both countries to urge closer co-operation in investigating the Mumbai attacks and in fighting terrorism generally".
A bomb blast in the Pakistani city of Lahore further raised tension
The BBC's Barbara Plett in Islamabad says the troop movements do not appear to be greatly significant and that both countries have said they want to avoid military conflict. However they warn they will act if provoked.
But our correspondent says any significant cut in the Pakistani military presence along the Afghan border would worry Washington, which relies on Islamabad to stem cross-border Taleban attacks on Nato forces.
India's Prime Minister Manmohan Singh discussed the Pakistan situation with his military chiefs on Friday.
The Indian foreign ministry advised Indian nationals not to travel to Pakistan following recent bombings in the Pakistani cities of Lahore and Multan.
One woman was killed and four people injured on Wednesday in Lahore.
Media reports said a number of Indians were detained although this has not been officially confirmed.
Indian foreign ministry spokesman Vishnu Prakash said in Delhi there were reports the Indians were "being accused of being terrorists".
"Indian citizens are therefore advised that it would be unsafe for them to travel or be in Pakistan."