The government could be inching closer to expelling the Russian ambassador, as the conflict between Ukraine and Russia escalates.
There has been global alarm at the Russian president's comments about nuclear war and plan to hold referendums in occupied regions of Ukraine on joining Russia.
Foreign Affairs Minister Nanaia Mahuta said there had been an "increased escalation of tension."
"It is not helpful on a number of fronts. Right now, as our prime minister is over at the UN, I am sure there will be a lot of conversations about next steps."
Vladimir Putin's comments had changed the government's position on whether or not to expel Russian Ambassador Georgii Zuev, Mahuta said.
The government had maintained the option to expel Zuev remained on the table since the start of Russia's invasion of Ukraine.
New Zealand had kept diplomatic channels open "in the hope that there is room for diplomacy", Mahuta said.
But a decision on whether or not to expel Zuev was now under active consideration and could "possibly" be made quickly, she said.
"The position of New Zealand is to keep open diplomatic channels in order to de-escalate the situation. But again, we assess our position in relation to the actions of Putin," Mahuta said.
"And right now hosting a referendum, that will impact on the sovereignty of Ukraine, appears to be an escalation rather than a de-escalation of the situation."
Previously, RNZ sent repeated requests for the ambassador for an interview, but his office only referred to a letter to Foreign Affairs, Defence and Trade Select Committee chair Jenny Salesa.
In the letter, he declined an invitation to brief the select committee, as Parliament debated whether he should be summonsed for questioning, saying it would be "obviously futile".
Mahuta said the war had entered a more "dynamic space".
"It appears that Putin is increasing his aggression against Ukraine and taking actions that contravene international law. By continuing to do that, that will be of concern to a number of like-minded partners who are helping Ukraine to defend itself."
In an apparently co-ordinated move, pro-Russian figures announced referendums for 23-27 September in Luhansk, Donetsk, Kherson and Zaporizhzhia provinces, representing about 15 percent of Ukrainian territory, or an area about the size of Hungary.
US National Security Adviser Jake Sullivan said Washington rejected any such referendums "unequivocally," and the European Union and Canada condemned the plan.
EU foreign policy chief Josep Borrell said the bloc and its member states would not recognise the outcome of the referendums.
European Union foreign ministers, who are in New York for the annual gathering of world leaders at the United Nations, have agreed to prepare new sanctions on Russia and increase weapons' deliveries to Kyiv in response to Putin's actions.
EU ministers will hold their next formal meeting in mid-October when a sanctions package could be formalised.
- With additional reporting by Reuters