A man rescued from a frozen Great Lake told officials he had been walking for two to three days in an attempt to get from Detroit to Toronto.

The US Coast Guard crew were astonished to come across the lone individual as their vessel broke ice on Lake St Clair, which lies between the US state of Michigan and the Canadian province of Ontario.

They said the unidentified 25-year-old man, dressed in ordinary clothing, was coming down with hypothermia.

US Coast Guard picked up the Michigan man just half a mile from Seaway Island on the Canadian shore.

Once there, it would have been another 220 miles (350km) by road to reach Toronto. 

Lake St Clair is 26 miles in length. 

Man Rescued Walking Across Frozen Lake To Canada

The American citizen told the crew he slept in a lighthouse on Wednesday night.

US Coast Guard Petty Officer Second Class Scott Sjostrom spotted him walking on the freshwater lake at around 9:30am on Thursday.

He said he noticed the individual was not wearing proper winter gear used for snowmobiling or ice fishing.

"That raised flags right off the bat," Officer Sjostrom told Mlive.

He and another coast guardsman left their 140ft (42 metre) tug to walk across the ice towards him.

Officer Sjostrom said: "When we got to him, you could tell the cold was getting to him.

"He was very lethargic ... He was shivering very bad."

He said the man was uncommunicative and had a "1,000-yard stare".

The man could have easily broken through the ice and drowned, added Officer Sjostrom.

US Coast Guard Lt Josh Zike said the man had a backpack containing food, clothes and a sleeping bag, but no flotation or communication devices.

He was taken for medical treatment in Algonac, Michigan.

It was the first rescue in four years by one of the Great Lakes ice-cutter boats, which clear the waterway for commercial shipping.