But speaking at the constitution, Europe, external affairs and culture committee, Mr Gray said he did not know how many people from Ukraine were currently in Scotland under the “super sponsor” scheme.
The initiative allows Ukrainian refugees to arrive in Scotland under the UK-wide Homes for Ukraine scheme, without having been matched with a volunteer opening their home to take in a family.
Mr Gray said data-sharing arrangements with the UK Government had not yet begun.
At the meeting, Scottish Green MSP Mark Ruskell warned thousands of Ukrainians already living in Scotland were being “totally failed” by the UK Government due to issues over visa schemes.
He said Ukrainians on seasonal work visas were still excluded from key humanitarian schemes for refugees set up by the UK Government, leaving them stuck in precarious employment, at risk of homelessness, and unable to be reunited with family from Ukraine.
"We have chosen to act as a super-sponsor to short circuit the matching process and enable significant numbers of displaced Ukrainians to come to Scotland without unnecessary delay,” he said.
"To prepare for that we have established welcome hubs to support displaced Ukrainians arriving into Edinburgh, Glasgow, and Cairnryan – where all those who need it will find safe and comfortable accommodation and a hot meal, and where local partnerships are already in place to make an assessment of need for additional services."
He said the Government was working "flat out" to secure temporary and longer-term accommodation for those who need it.
Mr Gray added: "As the First Minister said at the weekend, we will treat people with compassion, dignity and respect and Scotland will be their home for as they long as they need it to be."
Conservative MSP Donald Cameron asked him about the number of refugees who had arrived in Scotland since the super-sponsor scheme opened last week.
Mr Gray said he did not know the number. He said: "The data flows have not started as the way that we would want them to start as yet. We haven't got information in place.
"I don't believe that is because UK Government is holding it back from us.
"I just believe that the speed at which the system has been created – from First Minister's conception on one Friday to launch the following Friday – getting the system up and running has taken time."
A majority of those arriving so far were not doing so through the super-sponsor route, he said.
Mr Ruskell said while Ukrainian refugees arriving through the Homes for Ukraine or Ukraine Family Scheme are granted three years leave to remain and full access to public funds, the only concessions provided by the UK Government for Ukrainians on seasonal work visas is to extend their visas to December 2022. They remain excluded from the Ukraine Family Scheme and are barred from accessing social security.
He said: “We know that there are thousands of Ukrainian nationals working in farms across Scotland who are absolutely terrified for their families and loved ones in Ukraine, but can do nothing to bring them to safety. I’ve heard terrifying stories of Ukrainian workers on farms in Fife and Perthshire who are powerless to get their young children out of a war zone – this is nothing short of a scandal.
“It’s entirely within the power of the UK Home Office to fix this. But let’s be clear – the Tories in Westminster are choosing to exclude some Ukrainian refugees from protection. And the consequences are catastrophic."
Mr Ruskell added: “This is not what a functioning refugee protection system looks like. All those seeking safety from the war in Ukraine in Scotland need proper protection and support, regardless of whether they’re already here as a worker or recently arrived through new routes.
“A humanitarian crisis is not the time to be prioritising the smaller print on visas over people’s lives. The UK Government must act urgently to provide seasonal workers with the same rights and protections as other Ukrainian refugees.”Mr Gray said the Scottish Government was in live discussions with the UK Home Office on the issue.