NOT WELCOME: David Rovics has previously had trouble gaining entry to Norway and been barred from visiting Canada.

A radical American singer-songwriter set to perform in Nelson this evening has been denied entry into the country.

David Rovics has written political songs on topics such as the Iraq war and whistleblower Bradley Manning.

He was to play six concerts throughout New Zealand as part of his world tour, including at the Free House in Nelson tonight.

About to board a plane from Tokyo to Auckland on Tuesday, he received a phone call from Immigration New Zealand telling him he was not allowed in the country.

On a blog post titled "You Are Not Welcome in New Zealand", Rovics said the immigration agent asked why he was coming to New Zealand. He replied he was playing "six small gigs".

The agent asked if he would make any money, to which he replied he hoped to make "a little money". Rovics said he did not have a work permit, but hoped he could get one on arrival.

He was then questioned about being strip-searched on suspicion of drug smuggling in Norway.

He was also asked about being banned from Canada for a year when he tried to play a gig he did not have a work visa for.

Rovics quoted the agent as saying, "You can't board that flight. You're not welcome in New Zealand."

Rovics then asked if the agent had read his political blog, to which she responded she had.

A spokesperson for Immigration New Zealand confirmed Rovics had been barred from boarding the flight because he did not meet immigration entry requirements. These included having sufficient funds and the work visa required.

"Mr Rovics has openly talked on his blog about his drug use and being banned from Canada for providing false information to an immigration officer."

Rovics blogged: "If you've got any to spare for a stupid musician who didn't get a work visa to do six lousy gigs in a country that has three million people and 60 million sheep and is located in the middle of nowhere, your donations are very, very, very welcome."