A pastor at the epicentre of the deadly coronavirus outbreak is asking Christians around the world to pray as the death toll and number of infections continued to rise on Wednesday. 

At least 490 people have died from the virus, which first appeared in Wuhan, in China's Hubei province, in December.  As of Wednesday, there were over 24,000 cases worldwide, although the majority are in China. 

The unidentified pastor said in an open letter published by China Source that the outbreak was a "test of our faith". 

He described the situation as "so critical" but said that Christians there were trusting in God and praying for the city.

"It is readily apparent that we are facing a test of our faith," the pastor wrote.

"The situation is so critical, yet [we are] trusting in the Lord's promises, that his thoughts toward us are of peace, and not evil (Jeremiah. 29:11), and that he allows for a time of testing, not to destroy us, but to establish us.

"Therefore, Christians are not only to suffer with the people of this city, but we have a responsibility to pray for those in this city who are fearful, and to bring to them the peace of Christ."

He went on to say that although Christians had the peace of Christ, that peace "is not to remove us from disaster and death, but rather to have peace in the midst of disaster and death, because Christ has already overcome these things". 

"[When] disaster strikes us, it is but a form of God's love," he said.

"Spoken for today, Wuhan's pestilence cannot separate us from the love of Christ; this love is in our Lord Jesus Christ."

He asked Christians worldwide to pray for God's mercy on Wuhan, adding that it was especially the duty of Christians living in Wuhan to seek God's peace for the city, its people, officials and all those affected by the virus.