NATO on Friday condemned the entry of a Russian "humanitarian" convoy into Ukrainian territory without the consent of Ukrainian authorities, an event Ukraine charged was a "direct invasion."

And for the first time, NATO accused Russia of directly intervening in Ukraine, as Secretary General Anders Fogh Rasmussen said Russian artillery support was being employed against Ukrainian forces in eastern regions in which fighting has raged for months.

Rear Adm. John Kirby, a spokesman for the Pentagon, said it was an "unauthorized entry" and told Russia to "remove its vehicles immediately."

Rasmussen said the Russian convoy had entered into Ukraine without its government's consent and without any involvement from the Red Cross. He warned it would only escalate the crisis in the region to worrying levels, and he suggested it threw into question whether Russia's true purpose for providing the "humanitarian" aid was to supply arms to pro-Russian separatists.

"This is a blatant breach of Russia’s international commitments, including those made recently in Berlin and Geneva, and a further violation of Ukraine’s sovereignty by Russia," Rasmussen said. "It can only deepen the crisis in the region, which Russia itself has created and has continued to fuel. The disregard of international humanitarian principles raises further questions about whether the true purpose of the aid convoy is to support civilians or to resupply armed separatists."

In a statement earlier on Friday, Ukrainian President Petro Poroshenko said "a column of more than 100 vehicles entered Ukrainian territory without a customs inspection, without border control or International Red Cross escort, which is a flagrant violation of international law."

Rasmussen also said NATO has observed a "major escalation" in Russian military involvement in the region over the past handful of days, including direct artillery support both from across the border and within Ukraine.