A speaker at the Republican National Convention has said he believes Barack Obama is a Muslim who is 'with the bad guys' and supports the Middle East over the US.

Actor and former Calvin Klein model Antonio Sabato Jr spoke on the first day of the convention on the topic 'make America safe again', and told ABC Go in an interview after his speech that he felt in his heart the US president was not a Christian.

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"First of all I don't believe that the guy is a Christian. I don't believe that he follows the god that I love, the Jesus that I love," Sabato Jr. told the MSNBC hosts when asked why he did not think Obama had done a good job as president.

"I think he has an agenda from the beginning... he grew up if you follow his story, if you read his book if you understand about Obama – I mean that's not a Christian name is it?"

Questioned on why he believed Obama was not a Christian, despite him attending church, the actor continued: "Actually he does not attend church, he has never talked about Jesus Christ once. I have met a lot of Christian, I know Christian, I am one and I don't believe he is.

"It's in my heart, I see it for what it is. I believe he is on the other side... the Middle East. He is with the bad guys, he's with them, he's not with us. He's not with this country," he said.

When asked whether the country could ever have a Muslim or Jewish president, Sabato Jr responded: "We had one, we had a Muslim president for seven-and-a-half years."

The ABC hosts continued the interview by asking Sabato Jr if he believed Obama was Muslim, to which he responded: "Absolutely, absolutely. That's what I believe and you know what, I have the right to believe that and you have the right to go against it

"He grew up in that world, that's where he comes from, that's where he grew up," he added.