Pakistan will be held responsible if it did not make sincere efforts to curb terrorism and their safe harbour on its western border with Afghanistan, US Secretary of State Mike Pompeo has warned.

Speaking on Tuesday at the State Department, Pompeo said this was the message he delivered to the Pakistani leadership when he travelled to Islamabad last month after Imran Khan became prime minister. "We had made (it) clear that ... our expectation is that Pakistan will not provide safe harbour to terrorists on their western border," he said.