Many other countries are better placed than New Zealand to supply weapons to Ukraine, Foreign Minister Nanaia Mahuta says.
New Zealand has pledged an additional $5 million to support Ukraine, to include a contribution to a NATO trust fund that provides immediate non-lethal military assistance like fuel, military rations, communications and military first aid kits.
The government is also sending surplus defence equipment, consisting of body armour, helmets, camouflage vests and harness webbing.
The decision was made based on requests Ukraine has made to the international community and what New Zealand can immediately supply, Mahuta says.
"The protection equipment we've offered up are currently in the Defence stocks - we're able to release that fairly quickly."
Asked whether sending weapons would be a change in New Zealand's diplomatic response to the crisis, Mahuta told Morning Report that it would, noting the $6 million in humanitarian support.
New Zealand supported Ukraine's efforts to protect its sovereignty and territorial integrity, however there were many other countries with "stronger procurement" which were providing weapons and other lethal equipment, she said.
However the government was continuing to monitor the situation.
"We continue to assess and calibrate the nature of that effort as the war carries on as the potential further escalation happens."
An international court would need to determine whether Russian president Vladimir Putin's actions in Ukraine were a war crime, the minister said.
"But under no shadow of a doubt what he is doing is unjust, unprovoked and it is wrong."
Ukraine's allies have delivered planeloads of weapons shipments to bolster its military against the Russian invasion. Russia has criticised such deliveries from Nato member states.
Aid from the US includes a wide range of military equipment, ranging from 25,000 sets each of body armour and helmets to rifles and grenade launchers, thousands of other anti-tank weapons and more than 20m rounds of ammunition.
Besides Javelin missiles, the most powerful weapons include 800 Stinger anti-aircraft systems, once used to shoot down Soviet planes in Afghanistan.
- RNZ / Reuters / BBC