KYIV, Ukraine (AP) — Germany’s foreign minister arrived in Kyiv on Tuesday in the latest public display of support for Ukraine by its Western partners, although deliveries of promised weapons and ammunition from NATO countries like Germany have been slow and have left Ukraine vulnerable to a recent Russian push along parts of the front line.

Annalena Baerbock renewed Berlin’s calls for partners to send more air defense systems, as Russia pounds Ukraine with missiles, glide bombs and rockets. Germany is the second-biggest supplier of military aid to Ukraine after the United States.

Ukraine’s depleted troops are trying to hold off a fierce Russian offensive along the eastern border in one of the most critical phases of the war, which is stretching into its third year.

Germany recently pledged a third U.S.-made Patriot battery for Ukraine, but Kyiv officials say they are still facing an alarming shortfall of air defenses against the Russian onslaught.