Scotland faces tighter border restrictions beyond the scrapping of quarantine-free international travel.
SNP transport secretary Michael Matheson revealed three reviews of the way people are tested, traced and quarantined in the pandemic.
It comes after air corridors were finally scrapped despite months of warnings they were allowing unchecked spreading of deadly Covid-19.
Matheson said it was “fair” to be challenged on the time taken to end the scheme which exempts arrivals any quarantine rules for some countries deemed “safe”.
He said the policies were informed by experts and imposed at UK level and claimed travel corridors were seen as “effective” until last week when advice changed.
Challenged to explain why it took so long to end the corridors, Matheson told BBC Radio Scotland: “I think that is a fair point and a fair challenge to put to me.”
He said an official report to the UK advisory group in December made clear international travel was a “significant factor” in bringing it back during summer and autumn.
“The measures we’ve had since then have been viewed as being proportionate but there is no doubt in my mind we need to now look at what further measures we can put in place,” he added.
Matheson said officials are now looking at increasing capacity in contract tracing, reviewing any exemptions remaining for self-isolation and increasing testing for people arriving in Scotland.
Opposition politician and some experts have been calling for improvements in those areas for months.
The use of hotels for quarantine, used in other countries including Australia, is again being looked at as part of the wider reviews.
Matheson said the need for a negative test before travel is expected to be in place for most of the year.
