The United Nations Security Council is to hold emergency consultations today after Russia sent an aid convoy rolling into eastern Ukraine, where pro-Moscow rebels are fighting Kiev's forces.
Lithuania requested the meeting to be held at 3:00 pm (1900 GMT) to discuss the entry of scores of trucks that Ukraine has described as an "invasion."
The 15-member council will hear a briefing from senior UN official Oscar Fernandez-Taranco on the flare-up in tensions over the convoy that the West fears could be used to help separatist forces.
The United States and European governments had urged Moscow to work with Ukrainian authorities and the International Red Cross to verify the content of the cargo and ensure it arrives safely to civilians.
In Washington, the Pentagon demanded that Russia immediately pull out the convoy and warned of additional sanctions.
Ukrainian officials were blocked today from inspecting the content, according to the Ukrainian foreign ministry, and the Red Cross decided against accompanying the convoy due to security concerns.
At a news conference, Ukrainian Deputy Ambassador Oleksandr Pavlichenko called the Russian convoy a "blatant violation of our sovereignty" and said Kiev was not aware of the content of the cargo.
Russian Ambassador Vitaly Churkin however provided a list of the aid including electric generators, sugar, tea and baby food and scoffed at suggestions that these could have military purposes.
Asked about the aid helping the rebels, he responded: "With baby food?"
"The US do not have the monopoly on humanism," Churkin said. "If you are trying to question our humanism, I would resent that."
He insisted that Russia ordered the convoy to move after multiple attempts at reaching agreement with Ukraine for the deliveries failed.
"It was time to move and so we did," said the ambassador.
Churkin said he hoped that the Red Cross would help with the distribution of the aid to besieged civilians who have been without water and electricity for weeks amid an escalation of fighting.
Around 20 trucks entered the rebel bastion of Lugansk today, part of the nearly 300 lorries that have been waiting at the Russian border for a week.
UN Secretary-General Ban Ki-moon earlier this month said the United Nations would step up relief efforts to east Ukraine and noted that Kiev authorities were addressing humanitarian needs "appropriately."
Kiev has accused Moscow of fueling the insurgency, which erupted after Russia annexed Crimea in March, setting off the worst crisis between Russia and the West since the Cold War.
