Why does Ukraine want Long-Range Weapons to Strike Russia?

Russia raises the stakes in the Ukraine conflict. Promises to destroy deliveries of long-range missiles by US and Europe to Ukraine. This comes on the heels of US secretary of state Anthony Blinken and British Foreign Secretary David Lammy visiting Kyiv for discussions on military support. Volodymyr Zelenskyy has repeatedly called for restrictions on Western-supplied, long-range weapons to be lifted so his forces can strike airfields, ammunition depots, and command centres deep inside Russia.