Controversial American televangelist and leader of World Changers Church International Creflo Dollar has defended his call for supporters to help him buy a $65 million plane, saying the Devil is trying to "discredit" him.

"The enemy has got to discredit the voices of faith, and grace and truth, because he don't want you to know that you can walk on the water if you can look at Jesus," Dollar told his congregation in a sermon on Sunday.

"Let me tell you something about me believing in God: I can dream as long as I want to. I can believe God as long as I want to. If I want to believe God for a $65 million plane, you cannot stop me. You cannot stop me from dreaming. You can't stop me from dreaming! I'm going to dream until Jesus comes!"

Dollar faced criticism last month after his ministry launched an appeal to buy a Gulfstream G650 plane "so that our Pastors and staff can continue to safely and swiftly share the Good News of the Gospel worldwide". It was set to replace his old jet, which had to be taken out of service due to mechanical failures, but the appeal was later withdrawn.

Many condemned the cost of the plane, which is said to be the fastest civilian jet ever built, and Gospel singer Kirk Franklin accused Dollar of a "shortage of character".

"When a pastor wants people to buy him a private plane while a missionary in Somalia bathes children with sores, that's a shortage of character. When I camouflage my 'greeds' to look like 'needs', that's a shortage of character," Franklin wrote in a blog post.

"We don't have a shortage of greatness, we have a shortage of character."

Dollar was then accused of repeatedly refusing to open up about his finances, and being uncooperative in an inquiry conducted between 2007 and 2011. He reportedly owns a $2.4 million mansion in Fayette County, Georgia as well as a house on a private estate in Bergen, New Jersey. He preaches a prosperity gospel message.

In his latest sermon, Dollar says that those critcising his ministry don't understand it, and that he never asked his congregation for money, but instead relies on donors, many of them from abroad. He refuses to apologise for trusting in God to provide an expensive plane, and says he would go even further – to outer space.

"If you think a $65 million plane was too much – if they discovered that there's life on Mars, they're going to need to hear the gospel and I'm going to have to believe God for a billion dollar space shuttle. Because we got to preach the gospel on Mars. I dare you to tell me I can't dream! I dare you to tell me that I can't believe God" he said, to rapturous applause from his congregation.

"With God all things are possible to him that believes. And so I say to you, 'Dream on, baby. Dream on.' Don't dream about what you can have, dream about what the Devil says you can't have.

"Dream for the best, dream for the best healing, dream for the best deliverance, dream for the best house, dream for the best car. Just 'cause the world don't have it, don't mean you can't have it, you are children of the almighty God!"

Dollar finished by telling those gathered that they are in the "midst of a great fight" and the Devil is trying to stop people from talking about Jesus, but that God would prevail.

"You cannot stop, and you cannot curse, what God has blessed," he said.