Trump vows to improve vetting of migrants

US President Donald Trump says he will take new steps to keep the US safe and improve vetting procedures as he seeks to replace a legally challenged executive order blocking entry from seven Muslim-majority nations and suspending the US refugee programme.

"It is not compassionate, but reckless, to allow uncontrolled entry from places where proper vetting cannot occur," Trump said on Tuesday night.

"Those given the high honour of admission to the United States should support this country and love its people and its values."

Trump claimed most of those convicted of terrorism offences since the September 11, 2001, terrorist attacks were from other countries.

"We cannot allow a beachhead of terrorism to form inside America - we cannot allow our nation to become a sanctuary for extremists."