OpenUSD import in Unity with Materials

(I am new to usd format)I have imported NVDIA USD File assets in Unity and for this use the Importer by Unity (com.unity.importer.usd). It successfully showed the USD file in the scene as object but the problem is materials on the objects are missing. There are several objects all have material missing.
I have used Warehouse assets from NVIDIA Omniverse Asset Pack.

When I am expending the hirerchy in unity I see there is not materials under the object. is this the problem?

The warehouse page says they use MDL materials which Unity does not support.

Thanks you are right. Let me explore the alternatives.