(Reuters) - An Alaska man who was confronted over loitering by an employee of a Juneau bank was arrested after he indicated that he planned to rob the institution but was waiting for an acquaintance to arrive, police said on Tuesday.

Police officers responded to a report of a bank robbery threat at the Wells Fargo branch in downtown Juneau on Monday afternoon, and arrested 56-year-old John Knudson on a charge of criminal trespass, Juneau police said in a statement.

Knudson, who refused to leave the bank's premises when asked to do so by bank management, was not reported to be confrontational and was unarmed, but conveyed his plans to rob the branch, police said.

"A bank employee reported that Knudson indicated he was waiting for someone to arrive before he robbed the bank," the police statement said.

Knudson had apparently arranged some sort of a meeting with an acquaintance at the bank, but police later determined that that person was not involved in the robbery plan and was not charged, Juneau police spokeswoman Erann Kalwara said.

It was unclear whether the acquaintance was Knudson's brother, who was also at the scene but questioned and released after police determined he had no involvement.

Knudson was held at Lemon Creek Correctional Center on $500 cash bail, police said.

(Reporting by Eric M. Johnson in Seattle; Editing by Cynthia Johnston and Sandra Maler)