"I thought it was important for Australians to know that it is up to the job," Mr Morrison told reporters on Christmas Island.
"That the medical support that is necessary to do the job that is being required of this facility will be able to be delivered through the very professional staff of IHMS, who are also operating in Nauru itself, and will have a lot of familiarity with a lot of the cases."
Mr Morrison also confirmed that all asylum seekers and refugees that are approved for transfer under the medevac bill, will be sent to Christmas Island, rather than mainland Australia.
Doctors are yet to submit any applications for transfer since the bill became law on Friday.
"I think those who thought that this would be some easy passage to the mainland and would seek to try and take advantage and game the system, well, I think they are getting a very clear message that it won't be as simple as that," Mr Morrison said.
"They will come here to Christmas Island and this is where they will receive that assessment."
Mr Morrison said the centre is ready to house up to 250 people.
"That will ramp up very quickly," Mr Morrison said.
PM's motives questioned
Mr Morrison toured the North West Point detention centre and the medical and accommodation facilities.
He was also briefed by the Australian Border Force, as well as contractor Serco and medical experts.
Opposition Leader Bill Shorten described the prime minister's "frolic" as a waste of money, seizing on reports the Australian Border Force had fallen short on sea patrol targets due to budget cuts.
"What a waste of money ... you know, we find out they've cut the border force funding, then you've got a marketing campaign," he told a business summit in Sydney.
"The point about it is it's desperate stuff."
Human rights lawyer and National Justice Project director George Newhouse also questioned the prime minister's motives for the trip to Christmas Island.
"If the Prime Minister was interested in anything other than political posturing, he might make the time to visit Manus island and Nauru and speak to the hundreds of individuals who are suffering without adequate medical care," Mr Newhouse told SBS News.
Former refugee Dr Munjed Al Muderis speaks on Christmas Island reopening
Mr Morrison has visited Nauru and Manus Island as immigration minister in 2014, but not since becoming prime minister in August.
It is the first ever prime minister to visit the island on an official visit.
Catherine Stubberfield from the UN refugee agency said the key issue was providing medical care in an appropriate setting to sick asylum seekers and refugees.
"The long-term, arbitrary detention of any refugee or asylum-seeker is inappropriate; the re-detention of those who have already suffered immensely over the past six years would be even more harmful," she said.
"The key question is where refugees and asylum-seekers, who have done nothing wrong, may best recover.
"Those who are now ill among them are unlikely to recover in a remote, formal detention environment such as Christmas Island."
Refugees who fail Australia's character assessment
Most of the 57 men earmarked for Christmas Island detention have been classed as refugees under the government's processing procedures.
Details of 25 of those "adverse character cases" have been released showing some refugees are considered a risk because they have been accused of conducting a sexual relationship with a minor, possessing child pornography and "arrested for violent threats".
Other reasons given are "suspicious financial transactions", identity fraud, and suspected involvement in people smuggling.
At least four men whose applications for asylum have been rejected, are on the list with one allegedly being charged with murder and having a history of violence and another having "military service of interest.
The government has estimated reopening the mothballed centre will cost $1 billion, to fund upgraded medical facilities.
Supporters of the medevac bill have slammed the government's plan to send patients to Christmas Island, rather than hospitals on the mainland as was intended.
Asked about the trip on Tuesday, Mr Morrison said it was "regrettable" that Christmas Island had to be re-opened.
"I regret greatly that the advice of the Department of Home Affairs is that we would have to reopen Christmas Island in response to Labor's medevac bill which basically undermines and ends offshore processing as we know it today," he said.
Christmas Island was first used to house asylum seekers in 2001 and was shut down last year.
It has had a tumultuous history with several hunger strikes, protests and riots, as asylum seekers railed against the conditions and the length of their detention.
Additional reporting by AAP