Washington: The US has warned Pakistan that another terror attack on India will prove to be "extremely problematic" as it asked Islamabad to take more "concrete and sustained" actions.

Addressing reporters at the White House on Wednesday, a senior administration official said: "We need to see Pakistan taking concrete and sustained action to rein in the terrorist groups, mainly the Jaish-e-Mohammed and the Lashkar-e-Taiba, in order to ensure that we don't have re-escalation (of tensions) in the region".