The Indian government on Monday revoked Article 370 which gave special status to Jammu and Kashmir and proposed that the state be bifurcated into two union territories, Jammu and Kashmir, and Ladakh.
Reacting to the announcement, Pakistan Foreign Office said, "Jammu and Kashmir is an internationally recognised disputed territory" and "no unilateral step by the Government of India can change this disputed status."
The FO also said that Pakistan will exercise all possible options "to counter the illegal steps."
Foreign Minister Shah Mahmood Qureshi said Pakistan would request and appeal to the United Nations, Organisation of Islamic Cooperation, friendly countries and human rights organisations not to remain silent on this issue.
"We intend to firmly highlight our stance in our meetings with the US delegation visiting Pakistan and with the International Community at large," Qureshi said as he reaffirmed Pakistan's political, diplomatic and moral support to the people of Jammu and Kashmir.
The Indian move was also "strongly condemned" by Pakistani politicians, including Pakistan Muslim League-Nawaz (PML-N) president and opposition leader Shehbaz Sharif who termed it "unacceptable" and an "act of treason" against the United Nations.
He also called on the Pakistani leadership to immediately demand an emergency session of the UN Security Council and to consult with China, Russia, Turkey, Saudi Arabia and other friendly countries.
Jailed former prime minister Nawaz Sharif's daughter Maryam Nawaz lashed out at Prime Minister Imran Khan for "wreaking irreversible damage not only to the country but to Kashmiris who needed a strong Pakistan to support them."
In a series of tweets, Maryam, who is also vice-president of main opposition party PML-N, lambasted Prime Minister Khan for his failure to anticipate about the Indian government's plan on Kashmir.
Pakistan Peoples Party Chairperson Bilawal Bhutto Zardari also condemned the move.
Special Assistant to Prime Minister Imran Khan on Information and Broadcasting Dr Firdous Ashiq Awan said Pakistan will continue extending "moral, diplomatic and political support" to the Kashmiris.
Human rights minister Shireen Mazari termed the Indian move as "completely unacceptable."
"International Court of Justice must be approached immediately as well as moving the UNSC and other international forums including human rights organisation," she said.
Separately, the Parliamentary Committee on Kashmir would meet in Islamabad to discuss the latest situation.
Various Kashmiri groups and organisations protested in front of the Indian High Commission in Islamabad. The participants were carrying cards with pro-Kashmir slogans.
Meanwhile, Pakistan officials said that they organised a visit of defence attaches of different countries to the Line of Control to show them evidence of alleged use of cluster bombs by India.
The Indian Army on Saturday termed as "lies and deceit" Pakistan's allegations that Indian troops used cluster bombs targeting civilians along the Line of Control.
Pakistani officials said that diplomats from China, Russia, UK, France, Turkey and Germany were among the delegation visiting Kashmir.
"The team visited areas affected by Indian shelling and saw the damage done," they said.
The Neelum valley area was badly hit by the alleged Indian firing and pieces of ammunition are still scattered in the area.