On his first stop in a tour of three NATO-allied countries on the rim of the Black Sea, Austin signed a memorandum of understanding with his Georgian counterpart, Juansher Burchuladze, for a new military cooperation and training program.

"The United States condemns Russia's ongoing occupation of Georgia and its attempts to expand influence in the Black Sea region through military coercion and malign activities," Austin told Prime Minister Irakli Garibashvili, adding that the training scheme would help the country defend its borders.

"This is an important region and security and stability are crucial to fully realizing the vision that we share of a Europe that is whole and free and at peace."

The Pentagon chief praised Georgia's outsized contributions to the US-led coalition forces in Iraq and Afghanistan.

"Georgia has paid a heavy price," Austin said separately in a press conference with Burchuladze, pointing to 32 killed in Afghanistan. "The United States honors their sacrifice."

But, looking ahead, he stressed the two wars "do not define" the bilateral military relationship, and that Washington wants to help Tbilisi better defend itself.

Russia occupies 20 percent of Georgian territory, he said, referring to breakaway regions Abkhazia and South Ossetia.

"Our support for Georgia's sovereignty and territorial integrity is unwavering," he said.

Burchuladze told reporters that Georgia still hopes its cooperation puts it on a path to full membership in NATO, a longstanding wish that Austin did not address.

"We've signed a critically important document which brings us to a new stage of cooperation with the United States. It provides for bolstering Georgia's defence capabilities and a highest level of deterrence and compatibility with NATO standards," he said.

"The occupation is an everyday challenge. The occupation has different forms, different methods are being used against our country" from military to cyberattacks, Burchuladze added.

After Georgia, Austin heads to Ukraine, which also seeks full membership in NATO amid an ongoing war with pro-Moscow separatists, and then Romania, already a NATO member.

At the end of the week he is planning to attend the NATO defense ministers' conference in Brussels.