Kellan Lutz is ''happily single''.

The 'Hercules 3D' star denies he is dating Miley Cyrus - whom he has recently been spotted kissing in both Miami and Las Vegas - claiming they are just really good friends.

He told radio host Ryan Seacrest: ''Are we dating? No. It just makes me laugh. I've been friends with Miley for six years. She's a great girl... We are friends and we run in the same circle.''

Kellan, 28, also called Miley, 21, a ''cool secure woman'' and said he doesn't want to be in a relationship at the moment.

He added: ''I'm happily single ... I'm not [looking for a relationship] right now. I'm enjoying life and traveling quite a bit ... there's no real time to find the one.''

However, a source claims although Kellan and Miley are ''just enjoying themselves'' with their flirty behaviour, they have a ''great chemistry''.

The insider told E! news: ''They are both spontaneous, fun people, so their personalities match. They are having fun together. They have very similar outlooks. I am not sure if it has a future but they have great chemistry so for the time being they are just having fun.''