This is about keeping the terrorists out: Nikki Haley defends Trump's travel ban

US envoy to the UN Nikki Haley has said there should be no travel ban on the basis of religion, but defended President Donald Trump's executive order banning immigration from six Muslim-majority countries, saying it is meant to keep the country safe.

Haley said she believes that legal immigration is the "fabric" of America, pointing out that she is the "proud daughter" of Indian immigrants.

"I'm the proud daughter of Indian immigrants who reminded my brothers, my sister and me everyday how blessed we were to be in this country," she said responding to questions after her speech at the think tank Council on Foreign Relations here Wednesday.

She was asked if Trump's immigration policies and vetting people coming in from Muslim-majority nations carry the risk of alienating the three million Muslim-Americans already in the country.

"We should never ban based on religion. Period. I don't think that's what this is," she said, adding that there are another dozen Muslim-majority countries that could have been on the list of the seven countries on Trump's executive order but are not.

"We will never close our doors in the US but what we did do is take a pause and say how are we going to keep our people safe," she said while expressing hope that the vetting process gets better and the administration moves forward with it.

She said Trump's travel ban aimed to make sure that no danger comes into the US.

"This is not about not wanting people in. This is about keeping the terrorists out," she said.

Haley tried to further justify the ban by bringing up the recent terror attack in London. "When you look at situations like what happened in London, not just the President but everyone is trying to make sure we are keeping our people safe."

The attack on the UK Parliament was perpetrated by a man identified as Khalid Masood who, according to media reports, was not an immigrant but born in the county of Kent in southeast England.

She said the lack of "basic evaluation" in UN missions was "shocking" and cited the example of the mission in Afghanistan that has been in place for over 15 years but has never once been reviewed.

Calling this "unacceptable", Haley said "we are in the process of proposing a strategic review of this mission and other missions to get the facts on the ground." With peacekeeping bring the largest item in the UN budget, she said the review will identify the missions in need of structural reforms.

"We will determine where we need to augment, re-structure and cut back," she said, emphasising that the US is supportive of "better and smarter" peacekeeping operations not the ones that are "cheaper."

"We have to have the political will to adjust the missions even if some countries are going to lose funding in the process," she said.