Indian Prime Minister Narendra Modi has said that New Delhi has only paused military action against Pakistan, vowing to respond strongly to any future "terrorist attack".
Modi on Monday also warned that New Delhi would not tolerate "nuclear blackmail" in the event of further conflict with Pakistan.
A weekend ceasefire which US President Donald Trump said he brokered, appeared to be holding on Monday after four days of intense jetfighter, missile, drone and artillery attacks - the worst violence between the two nuclear-armed neighbours since 1999.
Trump said on Monday that US intervention had prevented a "bad nuclear war".
Modi, in a televised address to the nation – his first since hostilities began last Wednesday – said Pakistan has chosen to attack rather than help it fight "terrorism".
"If another terrorist attack against India is carried out, a strong response will be given," he said.
Modi also mentioned “We have only paused our military action against Pakistan”, suggesting a flare-up of hostilities is possible.
The conflict followed an April 22 attack on tourists in Indian-administered Kashmir which killed 26 civilians.
India accused Pakistan of backing the attack, but Islamabad denied involvement.
The telephone conversation, which follows a ceasefire agreement between the nuclear-armed neighbours after four days of deadly fighting last week, was earlier scheduled to take place at noon (0630 GMT).
Spiral to war
The alarming spiral towards all-out war began before dawn on Wednesday, when India launched missile attacks destroying what it called "terrorist camps" in the Pakistan-administered part of Kashmir.
Each side then accused the other of launching waves of warplane and drone strikes, as well as missile and artillery bombardments that killed at least 60 people on both sides.
"If Pakistan wants to survive, it will have to destroy its terror infrastructure," Modi said Monday.
"India will strike with precision and decisiveness against the terrorist groups thriving under the cover of nuclear blackmail.
"India's stand is very clear. Terror and talks cannot go together... Terror and trade cannot go together... Water and blood cannot flow together."
Indian missiles hit cities and mosques across Pakistan and Pakistan-administered Kashmir overnight.
His address came after the Indian army reported the "first calm night in recent days" in disputed Kashmir and along its western border with Pakistan.
The rivals also accused each other of breaching the ceasefire just hours after it was unexpectedly announced by Trump on social media on Saturday.
