It comes after reports of “chaos” on Monday, as delegates were forced to queue for hours to get into the venue on Monday morning.
Queues were also reported until at least midday on Tuesday morning.
In a Covid-19 update to MSPs on Tuesday, Mr Yousaf said the Scottish Government expects a risk of Covid-19 spread from the conference, and highlighted the issue of queuing.
"The scale and worldwide draw of COP26 poses risk of spread of Covid-19 both within the delegates and of course from the local population of Scotland and the UK,” he said.
A “comprehensive and exceptional” package of mitigation measures has been put in place to help prevent virus spread, Mr Yousaf said, including vaccination, ventilation, and a “robust testing regime”.
“Health Boards have planned and prepared for this event, and various arrangements including additional staff are in place to support delegates and other visitors while maintaining and protecting key health services,” he said.
Mr Yousaf added that queue management is the responsibility of the United Nations.
“The UK Government, as the event organisers, have put measures in place to manage access to the Blue Zone,” he said.
“Once inside the site itself, managing queues is the UN’s responsibility.
“We are liaising with the UK Government and Glasgow City Council to encourage the UN to put in place additional measures to avoid queues such as were seen in the media reports yesterday and – to a lesser extent – today.
"Of course while public health measures can mitigate the spread of Covid-19 to an extent, there remains a risk that COP26 could increase the spread of the virus.
"That is why Covid-19 continues to be closely monitored by all relevant agencies, and why the Scottish Government will be closely involved in operational decisions during the event.”
Mr Yousaf also warned that the Scottish Government "will not hesitate” to strengthen existing Covid-19 restrictions if necessary, as the NHS continues to struggle in the run up to winter.