Donald Trump promised faith leaders on Thursday that he was committed to protecting religious freedom and the dignity of the unborn. 

In a warmly received address at the National Prayer Breakfast, the US President told his audience, comprised of Muslims, Jews and Christians: 'I will never let you down - never.'

Receiving a standing ovation at one point, Trump vowed to 'build a culture that cherishes the dignity and sanctity of innocent human life'. 

'All children, born and unborn, are made in the holy image of God,' he said.

He also promised to protect the right of people of faith to live out their beliefs in their communities. 

'Every day, the people in this room demonstrate the power of faith to transform lives, heal communities and lift up the forgotten,' he said.

'As president, I will always cherish, honor and protect the believers who uplift our communities and sustain our nation to ensure that people of faith can always contribute to our society.' 

This included allowing faith-based adoption agencies to find new homes for children in line with their religious beliefs, he said, referring to an ongoing court case involving St Vincent Catholic Charities over its refusal to place children with same-sex couples.   

'We will always protect our country's long and proud tradition of faith-based adoption,' said Trump.

'My administration is working to ensure that faith-based adoption agencies are able to help vulnerable children find their forever families while following their deeply-held beliefs.' 

It is the second time in a week that Trump has appealed to his evangelical base after attacking late-term abortion in his State of the Union address. 

'There could be no greater contrast to the beautiful image of a mother holding her infant child than the chilling displays our nation saw in recent days,' he said.

'Lawmakers in New York cheered with delight upon the passage of legislation that would allow a baby to be ripped from the mother's womb moments before birth.

'These are living, feeling, beautiful babies who will never get the chance to share their love and dreams with the world.'

In the speech on Tuesday, Trump said he would ask Congress to pass legislation prohibiting the late-term abortion of children who can feel pain in the mother's womb. 

'Let us work together to build a culture that cherishes innocent life. And let us reaffirm a fundamental truth: all children – born and unborn – are made in the holy image of God,' he said.