WASHINGTON (REUTERS) - President Donald Trump unveiled a new national security strategy on Monday (Dec 18), calling for Pakistan to take decisive action against terrorism and saying Washington had to deal with the challenge posed by North Korea's weapons programmes.

In a wide-ranging speech, Trump said his security strategy for the first time addresses economic security and would include a complete rebuilding of US infrastructure as well as a wall along the southern US border.

Trump said the United States wanted Pakistan to take decisive action to help fight extremism, and that Washington had "no choice" but to deal with the challenge posed by North Korea's nuclear and missile programmes.

Trump said the security strategy would also end mandatory defense spending limits, frequently called "sequester", but did not mention if he had consulted with members of Congress about a possible Bill to end the caps established in 2013 Budget legislation.

"We recognise that weakness is the surest path to conflict and unrivaled power is the most certain means of defence. For this reason, our security strategy breaks from damaging defense sequester," Trump said. "We're going to get rid of that."