The US dentist who killed Cecil the Lion has defended his actions as he said he expects to be back at work within days.

Walter Palmer faced a global backlash after it emerged the lion, a popular attraction at Hwange National Park in Zimbabwe, had been killed on a hunt.

In an interview with the Associated Press and the Minneapolis Star Tribune, Mr Palmer repeated his belief that he acted legally and that he did not know Cecil was one of Zimbabwe's most treasured animals.

"If I had known this lion had a name and was important to the country or a study obviously I wouldn't have taken it," Mr Palmer said.

"Nobody in our hunting party knew before or after the name of this lion".

Mr Palmer also said he intends to go back to work at his suburban Minneapolis dental practice on Tuesday, which was temporarily closed as the controversy surrounding the killing raged.

"My staff and my patients support me and they want me back," he said.

The dentist said he shot the big cat, which was fitted with a GPS collar as part of research, using an arrow from his compound bow outside the park's borders.

Mr Palmer said Cecil did not die immediately and was tracked down the next day before being killed with an another arrow - not a gun as conservationists have said.

He declined to answer questions about how much he paid for the hunt or others he had taken part in.

"Walter doesn't need a lawyer"

There were calls for Mr Palmer to be extradited in the wake of the killing, but Joe Friederg, an attorney who said he is acting as an unpaid consultant to the dentist, said he has heard nothing from the authorities about domestic or international investigations since the start of August.

"I'm not Walter's lawyer in this situation because Walter doesn't need a lawyer in this situation," Mr Friedberg said.

"If some governmental agency or investigative unit would make a claim that he violated some law then we'd talk about it".

Two people are facing charges in Zimbabwe in connection with the hunt.

Theo Bronkhorst, a professional hunter who helped Palmer, has been charged with "failure to prevent an illegal hunt".

Honest Ndlovu, whose property is near the park in western Zimbabwe, faces a charge of allowing the lion hunt to occur on his farm without proper authority.

Mr Palmer described himself as "heartbroken" for causing disruption to staff at his clinic, which was closed for a month and re-opened in late August without him.

He added the ordeal has been particularly difficult for his wife and adult daughter, both of whom he said felt threatened.

"I don't understand that level of humanity to come after people not involved at all," Mr Palmer said.

Mr Palmer did not say where he had spent the last week, but insisted he had not been "in hiding".

The killing of Cecil sparked a debate about trophy hunting in Africa, and Zimbabwe tightened the regulations for lion, elephant and leopard hunting after the incident.

Three US airlines also changed their policies to outlaw the shipment of the trophies.