He said there were "occasions where things blew up it was always good just to hear directly [from ambassadors]".
He said that in the case of Russia, Mahuta should have been on the phone to get a sense of the embassy staff's safety and the mood in Russia.
Brownlee said because ambassadors are ministerial appointments, the relationship between the Beehive and the ambassador was significant.
Mahuta has had at least 11 significant engagements she has had since February.
A spokeswoman for Mahuta said the "Ministry of Foreign Affairs and Trade is in ongoing contact with the embassy in Moscow, including regular calls".
"The secretary of MFAT and senior officials use the information to provide updates and briefings for the minister, along with formal messages reported by Mfat's wider international network of ambassadors and posts," she said.
The spokeswoman added the embassy in Moscow was "a critical part of a large network of foreign posts that feed information into the situation reports on Ukraine and Russia that are prepared by MFAT. The minister received MFAT SitReps twice weekly in the immediate aftermath of the invasion. These are now provided weekly".
The Government has created two groups inside MFAT to respond to the crisis in Ukraine: the Ukraine Response Unit and the Russia Sanctions Taskforce.
Both units co-ordinate all global communications and advice on Ukraine.
Communications from Moscow, other foreign capitals, and organisations like Nato, the United Nations, the European Union, the International Criminal Court, the Red Cross, and the International Monetary Fund, all go through MFAT.
On Wednesday, Mahuta announced she had met virtually with her Solomons Island counterpart - the first contact between the pair since that nation signed a controversial security pact with China.
Mahuta and Defence Minister Peeni Henare today also announced the New Zealand Defence Force deployment to Solomon Islands would be extended another year.
