The Ministry of Foreign Affairs website was attacked by hackers on Saturday, officials from the ministry said.
According to the spokesperson, Dr Mohammad Faisal, complaints were received by the ministry from various countries reporting that the website was inaccessible there.
"The IT team is currently occupied in thwarting the hackers' onslaught," he said.
The spokesperson added that the website is functioning without any issues in Pakistan. However, visitors to the website from Holland, Australia, Britain, and Saudi Arabia are facing difficulty opening it.
The attacks are believed to be of Indian origin, sources within the ministry told DawnNewsTV.
Cross-border hacking attacks have been sporadic yet common since at least 1998.
Hackers claiming to be from Pakistan defaced websites of seven Indian embassies, high commissions, and consulates in various countries with pro-Pakistan Army slogans in July 2016.
Prior to that, in 2015, Pakistani hackers attacked the National Institute of Technology (NIT) Raipur's website.
A year earlier, in 2014, the Lahore High Court's website was attacked and defaced by Indian hackers.