Liow Tiong Lai told the BBC that search teams would keep looking for the aircraft which had been carrying 239 passengers and crew.
The Malaysian airliner was on its way from Kuala Lumpur to Beijing when it vanished.
Investigators are due to release a report on the search on Sunday.
Australia is leading an international search team in the southern Indian Ocean, approximately 1,600km (1,000 miles) off its west coast.
Could it have been suicide?
What we know
How the search is conducted
Malaysian police say they are still investigating whether the plane's disappearance was intentional but have not revealed any details of their findings, the BBC's Jennifer Pak reports.
Earlier this year, the Malaysian government declared flight MH370 to have been lost with all on board, in a move it said was necessary to start processing compensation claims for the families.
But Mr Liow promised his government would continue to back the search operation.
"We are confident we can complete the search hopefully by May this year, and we hope we can get the plane," he said.
If the scan of the designated search area did not yield any result by May, investigators would go "back to the drawing board", he told AFP news agency.
That would mean re-examining all available data that was used to determine the crash zone.
Some families of those on board the plane have accused the Malaysian authorities of hiding some information, but the transport minister urged them not to "believe in all the conspiracy theories".
"[They] have to believe in data, facts, in... experts who give us the data that shows that - proves that - this plane is in the south Indian Ocean," he said. "And that is why we are focused in that area."
The family of the flight's pilot has said there is no evidence to suggest Zaharie Ahmad Shah was responsible for the aircraft's disappearance.
His sister, Sakinab Shah, issued a media statement online to deny renewed speculation that her brother had intentionally flown the plane to avoid detection.
She said no-one had the right to blame her brother without any proof.
Of all the many theories about what happened to MH370, the idea that it might have been diverted to a remote airfield and its passengers taken off, seems the least plausible. What motive could the mysterious hijacker have had? No demands have been made.
But it is a theory that Wen Wan Cheng is clinging to with defiant certainty. And who can blame him? The 64 year-old property developer from Shandong had his son, Wen Yong Sheng, on board the ill-fated flight. Until he sees some evidence of what happened to the plane, he believes his son must still be alive.
The Malaysian authorities still insist the best theory is that the plane crashed into a remote part of the southern Indian Ocean, after being diverted and flying south for several hours. That is where they are still looking, in 60,000 sq km (23,166 sq m) of sea.
But they lost the trust of the families early on due to their clumsy and confused response to the disappearance. The inexplicable absence of any wreckage, one year on, allows relatives to hold on to the near-impossible hope that some of the 239 passengers and crew may have survived.
Malaysia's transport minister says he is confident the MH370 flight which disappeared almost a year ago will be found in the southern Indian Ocean.