This past week has seen the most significant escalation in hostilities Ukraine has witnessed since Russia's full-scale invasion and marks a new chapter in the nearly three-year war.

In the week that saw the conflict pass its 1000th day, Western powers substantially boosted Ukraine's military arsenal - and the Kremlin made its loudest threats yet of a nuclear strike. Here is how the last week played out - and what it means.

President Joe Biden has reversed some of his own policy positions on Ukraine even as Russia has used new tactics in the conflict and warned of escalation. Ukraine says Russia launched an intercontinental ballistic missile,