Tony Blair has vowed not to soften his crackdown on terrorism and its supporters either at home or abroad.
Blair says a clear, international message has to be sent
Speaking during his visit to India, Mr Blair said he was determined to press ahead with moves in both the UN and the Commons to tackle the issue head-on.
He said he believed there was a mood for a tough UN declaration coming from other countries.
And he said there was a line to draw over UK freedom of speech - one which terrorist supporters were crossing.
That would anger the British people who would quickly start to think their natural tolerance was being abused, Mr Blair warned.
He also praised his Home Secretary Charles Clarke and dismissed any suggestion he wanted to sack him.
On proposals for a statement from the UN meeting next week, he said: "I detect the mood is quite tough for action on that."
"The important thing is to send a very clear signal from the international community," he insisted.
Turning to his controversial planned laws at home, he said he expected them to be challenged in the courts but was not about to back down.
"We are not stopping any freedom of speech. But with freedom comes responsibility and you have to draw a line.
"If you do not draw the line people get very frustrated and angry and think their tolerance is being abused "You have to make a judgement in the end about what is right and what is wrong.
"We have to take that clear line and we have to see it through.
"I set the process out very deliberately. We are going to take these measures. They will be tested in the courts and let us see what happens," he said.
Home Secretary Charles Clarke was an "immensely effective" home secretary, he said, adding: "He does not just carry authority but he implements the measures and takes absolutely the right steps".
Claims he wanted to sack Mr Clarke were just wrong, the prime minister insisted.
And repeating his praise for the way the UK reacted to the London bombings, Mr Blair said: "The British people demonstrated remarkable maturity that won plaudits around the world."
But, like him, they expected a line to be drawn with people advocating and encouraging terrorism.
Speaking earlier after an India-European Union summit, the prime minister's spokesman said Britain was seeking support for a draft resolution to commit countries to act against those within their territory who incite terrorism, not just those who commit it.
Mr Blair, on the second leg of his tour of Asia, will be among leaders attending next week's world summit to mark the 60th anniversary of the UN.
The EU and India pledged to boost anti-terrorism cooperation and crack down on terrorist financing and other money laundering at Wednesday's summit, the two sides said in a joint statement.
Mr Blair hailed the agreement as a "turning point" in relations between the two economic powers.
The "action plan" with India will point the way to greater co-operation between the EU and India, Mr Blair said.
The prime minister also saw a deal signed to involve India in the satellite navigation system called Galileo, which is a competitor to the United States' global positioning system.