More than 500 evangelical pastors and ministry leaders representing every state in the US have signed a letter published in yesterday's Washington Post expressing grave concern over Donald Trump's refugee policy.

The letter comes as Trump's executive order banning refugees from seven Muslim-majority countries makes its way through the courts.

It was coordinated by World Relief, one of nine agencies nationally authorised by the US State Department to resettle refugees.

"We live in a dangerous world and affirm the crucial role of government in protecting us from harm and in setting the terms on refugee admissions. However, compassion and security can coexist, as they have for decades," says the letter, addressed to Trump and the Vice President Mike Pence.

"While we are eager to welcome persecuted Christians, we also welcome vulnerable Muslims and people of other faiths or no faith at all. This executive order dramatically reduces the overall number of refugees allowed this year, robbing families of hope and a future."

The letter notes how thousands of local American congregations have welcomed newly arrived refugees of all faiths through the Refugee Resettlement Program and how these churches and other ministries still have the desire to welcome many more.

"As Christians, we have a historic call expressed over two thousand years, to serve the suffering. We cannot abandon this call now," it states.

Signatories include the authors Tim and Kathy Keller, senior pastor Bill Hybels and author Lynne Hybels, Northland Church senior pastor Joel Hunter, National Association of Evangelicals President Leith Anderson, New York Times bestselling author Ann Voskamp, Southeastern Baptist Theological Seminary President Daniel Akin, and Open Doors USA President and CEO David Curry.

"It is not new for the church to use its voice on behalf of those who have none. It is part of our historic call and identity. And for nearly four decades World Relief has helped thousands of churches and tens of thousands of volunteers express that call by welcoming refugees. This letter is evidence that the church will not abandon its calling to serve the most vulnerable," said World Relief President Scott Arbeiter.

Ed Stetzer of Wheaton College added: "Christians have always spoken up for the vulnerable. I hope the Trump administration hears our concerns that we have a safe and compassionate refugee policy—and our confidence that we can continue to do both."

Lynne Hybels said: "For some people, embracing refugees is a political issue. For me, as a Christian, speaking up for and caring for refugees is more an act of worship and obedience to a God whose Kingdom is global and whose 'mercies are new every morning.' On a personal level, my life has been profoundly enriched by the courageously resilient refugees I've known in Jordan, Lebanon, Iraq, and the Democratic Republic of Congo, as well as in Illinois and Michigan. I hope many more American Christians will be able to enjoy the rewards of such mutually transformational relationships."