Ukrainian President Volodymyr Zelensky on Monday thanked Romania for its aid to his country, which has been facing a major Russian military invasion for several days."I am grateful to Romania for its significant contribution to our country's defence capabilities. I am grateful to @KlausIohannis for supporting Ukraine's accession to the European Union. We feel the political and defence support of our partners," the head of the Ukrainian state wrote on his Twitter account, @ZelenskyyUa.European Commissioner for Home Affairs Ylva Johansson also thanked the Romanian authorities and citizens for the way they came to the aid of the Ukrainian refugees.My most important message is: thank you, Romania. (...) The weather is very cold, but the welcome is warm. In these very difficult times, when we see war again in Europe, when we see Putin's aggression on a neighbour, sovereign country, to see how the citizens of Suceava County, Romanians from all over the country, the civil society, the authorities warmly welcome the refugees is emotional. By showing solidarity, we are showing that we rely on values other than Putin's, and we are putting those values into practice. In the past few days, we have seen unity, a firm action (...) on the part of the European Union, as we have never seen before, because it is necessary," said Ylva Johansson on Monday, at the end of a visit to the refugee camp in the area of the Siret Border Crossing Point.She said she was impressed with the way the Romanian authorities and citizens acted, but underscored the need for the European Union's involvement in providing financial, material and human resources support.Romania decided on Sunday to send to Ukraine a second tranche of aid totaling 3 million euros, in the form of fuel, bulletproof vests, helmets, ammunition and military equipment, food, water and medicine. At the same time, the executive in Bucharest announced its readiness to take over injured Ukrainians in the Romanian health network.According to UN estimates, four million Ukrainians are expected to leave their country as refugees. Most of them are women and children, given that Ukrainian men between the ages of 18 and 60 are required to remain in the country under the state of emergency.