Addressing the top world body, Imran Khan said: "If a conventional war starts and anything could happen, supposing a country seven times smaller than its neighbour is faced with the choice, either you surrender or you fight for your freedom till death; And I asked myself this question, and my belief is 'La-ilaha-illallah', there is no God but one, and we will fight."
He said when a nuclear armed country "fights to the end, it will have consequences far beyond the borders, it will have consequence for the world".
"I am warning you, it is not a threat, it's a fair worry... Where are we headed," he asked, urging the UN to intervene on Kashmir.
He also referred to the Congress in India. "The previous Congress Home Minister gave a statement that in RSS camps, terrorists are being trained, and these terrorists butchered 2,000 Muslims while 150,000 were made homeless," he said.
Referring to the RSS, he said: "Now I must explain what RSS is. Modi is a life member (of RSS). They believe in the ethnic cleansing of Muslims."
In an openly radical Islamist statement, Imran Khan, who exceeded the talk time allocated to him by a fair margin, said that the Muslims in India, which has the second largest population of Muslims in the word, would get radicalised watching the Kashmiris.
"Don't you think they too will be radicalised? Then there will be blame on us again," he said.
"Muslims will become radicals because of this, not because of Islam. Because they see no justice."
Ignoring his own country, its people, its problems and its minorities, Imran Khan chose to focus solely on Kashmir.
He warned that there "will be a bloodbath" in Indian Jammu and Kashmir when the curfew is lifted. "What happens then? Has anyone thought about that," he asked.
Targetting Prime Minister Narendra Modi, he said: "Illusions of racial superiority and arrogance lead people to make mistakes and cruel decisions," referring to the August 5 revocation of Articles 370 which granted special status to Jammu and Kashmir.
Imran Khan warned that "there will be another Pulwama and then India will blame Pakistan," referring to the February 14 suicide attack in Pulwama, in which 40 Indian security personnel were killed by a Jaish-e-Mohammed operative.
He also accused India of trying to push Pakistan to the Financial Action Task Force blacklist.
"The RSS believes in ethnic cleansing of Muslims and PM Modi is a leader of the RSS," he said.
On Islamophobia, he said that before 9/11, the majority of suicide attacks "were carried out by Tamil Tigers who were Hindus, but no one blamed Hinduism".
"The Prophet lives in our hearts," he said to loud cheers from a section of the audience.
"When the Prophet is ridiculed, the pain of the heart is far, far more hurtful than physical pain. That's all we ask, do not use freedom of speech by insulting our Holy Prophet," he said.
After the speech, Pakistan Foreign Office spokesperson Mohammad Faisal tweeted: "Many Muslim diplomats were in tears when PM referred to the Prophet. PM has made a strong case for Muslim ummah and for Pakistan. The speech will be remembered and referred to in the times to come."
( With inputs from IANS )