In a message to the Ukrainian people dated 28 February 2022, the Synod of the Ukrainian Orthodox Church of the Moscow Patriarchate clearly condemns the war and declares its support for the state sovereignty and territorial integrity of Ukraine:

Address of the Holy Synod of the Ukrainian Orthodox Church of 28 February 2022

Beloved in Christ Most Reverend Hierarchs, Fathers, Brothers and Sisters!
Dear Ukrainian people!
With sorrow and pain we are experiencing that war has come to our native Ukrainian land. Severe trials have befallen us all. Fighting between the troops of the Russian Federation and the Armed Forces of Ukraine continues almost all over Ukraine, warriors and civilians are dying and the number of refugees is growing. Putting nuclear weapons on high alert in general puts into sharp question the future existence of humanity and the world at large. In such a difficult situation, we call on everyone to be courageous, to increase prayer and to unite around the defence of our homeland.
To all our defenders, we want to testify that we honour you and pray for you, for you risk your lives sacrificially and testify how one can fulfil the words of our Lord Jesus Christ: No greater love is possible, than when one lays down one's life for one's neighbour (John 15:13).
For our part, we reaffirm that the Ukrainian Orthodox Church has always supported and supports the state sovereignty and territorial integrity of Ukraine. We fully share the pain and suffering of our people. In these important days in all churches and monasteries of our Church we pray intensively for the end of war and restoration of peace in Ukraine. With the blessing of His Beatitude Metropolitan Onuphry, dioceses and monasteries provide comprehensive assistance to refugees and all those who have suffered as a result of the fighting. Our churches are open round the clock to those in need of protection from shelling. The Ukrainian Orthodox Church is expanding its mission to help all those in need every day.
Being aware of the special spiritual responsibility, we address today His Holiness Patriarch Kirill of Moscow and All Russia. Your Holiness! We ask You to strengthen our prayers for the long-suffering Ukrainian people, to say Your word as the first hierarch to stop the fratricidal bloodshed on Ukrainian soil and to call on the leadership of the Russian Federation to immediately stop the hostilities, which are already threatening to turn into a world war.
We also address the President of Ukraine, Vladimir Aleksandrovich Zelensky, and the President of the Russian Federation, Vladimir Vladimirovich Putin. On behalf of the millions of members of the Ukrainian Orthodox Church, we ask that you do everything possible to put an end to the sin of armed confrontation between our two brotherly peoples and begin the negotiation process. This terrible war has already dealt a heavy blow to relations between the Ukrainian and Russian peoples. If the bloodshed is not stopped, the chasm between our peoples may remain forever.
Ukrainian people, brothers and sisters! We hope that common sense will prevail and that this war will end soon. We ask each of you to keep peace between yourselves and not to give in to provocations. Give help to one another, take care of one another. It is also important not to incite enmity among yourselves. Only in unity can we be strong. We pray that the Lord will illuminate the rulers with the light of His grace. We believe that the merciful Lord will accept our work of prayer and forgive us our sins. And in the near future the peace of God will reign again on our blessed Ukrainian land!

Source: Quelle: https://news.church.ua/2022/02/28/obrashhenie-svyashhennogo-sinoda-ukrainskoj-pravoslavnoj-cerkvi-ot-28-fevralya-2022-goda/?lang=ru (translation: Barbara Hallensleben)