A MAN at the centre of a police standoff in Brisbane after threatening to harm himself, has asked officers for a McDonald's bacon and egg McMuffin.

A 100-metre exclusion zone has been set up around Eagle St pier and police and a bomb detection robot are at the scene where the 54-year-old man, a New Zealand army veteran, has moored his boat at the inner-city wharf.

In a phone call with The Courier-Mail, the man told of personal issues and said he was prepared to maintain his standoff for two weeks.

Police say he called them about 5am (AEST) today threatening to harm himself but they would not confirm if any explosive devices were onboard the yacht.

However, the man has been seen holding a jerry can and a 30cm-long bayonet.

A police officer said at the scene the man had requested a bacon and egg McMuffin.

However, the request has been made after McDonald's 10.30am (AEST) breakfast cut off time.

Police say they are trying to fulfill the request.

The man has been seen playing a guitar onboard after police negotiators pulled back about 10.30am (AEST).

Police Inspector Shane Dall'Osto earlier said officers hoped for a peaceful resolution.

Inspector Dall'Osto refused to respond to questions about what the man's threats of self harm involved.

He said the man was alone on the boat.

Fellow yachtie and friend "Mack" said he was a "lovely, lovely bloke".

"It's possibly a call for help," he said at the scene.

("Although) he wouldn't be seeking or anticipating attention of this scale."

The riverside walkway, Eagle St pier, riverside ferry terminals, along with the Eagle St city area and the Brisbane River between Holman and Thornton sts are all closed.

For local updates and pictures, visit The Courier-Mail.

Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14 or SANE Helpline on 1800 18 SANE (7263).