The United States slammed Russia for sending convoy carrying humanitarian aids to Ukraine cities, saying such act represents "extremely dangerous and provocative escalation."

The United States slammed Russia for sending convoy carrying humanitarian aids to Ukraine cities, saying such act represents "extremely dangerous and provocative escalation."

There has been an "escalation" in Russian activity in recent weeks to unsettle the already tense situation on the ground in eastern Ukraine, National Security Council spokeswoman Caitlin Hayden said in a statement.

Russia and neighboring Ukraine have been wrangling for days over a Russian convoy carrying humanitarian aid for besieged cities held by pro-federalization activists but which Kiev says could be a "Trojan horse" to provide military help to the insurgents.

"Even as we work to gather information (about the partial destruction of the Russian armored column), we reiterate our concern about repeated Russian and Russian-supported incursions into Ukraine," Hayden said.

"Russia has no right to send vehicles, persons, or cargo of any kind into Ukraine, under any pretext, without the government of Ukraine's permission."

Hayden warned that "the escalation in Russian activity designed to destabilize Ukraine in recent weeks is extremely dangerous and provocative."

"It includes supplying separatist fighters with tanks, armored vehicles, artillery and multiple rocket launchers (MRLs)," she added.