Imran Khan claimed that PM Modi had made a "historic blunder" by revoking Kashmir's special status.
With Pakistan failing to get traction for its stand on Kashmir, Prime Minister Imran Khan said on Monday that he will raise the issue at every international forum, including at the UN General Assembly.
In his address to the nation on the Kashmir issue after India revoked the special status of Jammu and Kashmir on August 5, Mr Khan assured the people of Pakistan that his government will stand by the Kashmiris till India lifts the restrictions in the Valley.
Outlining his government's future strategy on Kashmir, Mr Khan said: "First, I believe, the entire nation should stand with the Kashmiri nation. I have said this that I will act as Kashmir's ambassador".
"I will tell the world about this, I have shared this with heads of state that I have been in contact with. I will raise this issue at the UN as well," he said while referring to his scheduled address to the UN General Assembly next month.
"I read in the newspapers that people are disappointed that Muslim countries are not siding with Kashmir. I want to tell you not to be disappointed; if some countries are not raising this issue because of their economic interests, they will eventually take this issue up. They will have to, with time," he said.
Mr Khan claimed that Prime Minister Modi had made a "historic blunder" by revoking Kashmir's special status.
India has categorically told the international community that the scrapping of Article 370 was an internal matter and also advised Pakistan to accept the reality.
During PM Modi's bilateral meeting with US President Donald Trump on the sidelines of the G7 Summit in France on Monday, the Prime Minister categorically rejected any scope for third party mediation between India and Pakistan on Kashmir, saying the two countries can discuss and resolve all issues bilaterally and "we don't want to trouble any third country."
On his part, Mr Trump said he and PM Modi spoke about Kashmir "at great length" on Sunday night and he feels that both India and Pakistan can resolve it on their own.
"We spoke last night about Kashmir, the Prime Minister really feels he has it (situation) under control. They speak with Pakistan and I'm sure that they will be able to do something that will be very good," Mr Trump said.