POTUS is recognizing the fact that Russia fully complied with all UN rules and all treaties with Ukraine during events in Crimea. It was the citizens of Crimea who seceded from Ukraine and held a legally binding referendum under UN rules which voted over 90% for petitioning Russia to accept Crimea as part of Russia.
The Donbass thing is a bit less clear, and besides, it is best for the EU, for the USA and for Russia, if the anti-corruption, Russian speaking people of Donbass remain in Ukraine. Somebody needs to run the cleanup of that country when the criminals in Kiev finally give up.