BRUSSELS (Reuters) - Russia's missile strikes on Ukraine have laid bare the "malice and cruelty" of its war and further united the international community to support Ukraine's military efforts to defend itself, U.S. Defense Secretary Lloyd Austin said on Wednesday.

Austin, speaking at the start of a Ukraine-focused meeting at NATO headquarters, praised Ukraine's military gains since September, calling them "extraordinary" and saying they had changed the dynamics of the war.

"These victories belong to Ukraine's brave soldiers. But the Contact Group's security assistance, training, and sustainment efforts have been vital," Austin said, addressing the gathering of defense leaders, including from Ukraine.

(Reporting by Phil Stewart and Sabine Siebold; Editing by Andrew Heavens)