MOSCOW (Reuters) - Russia wants to know more details about U.S. plans to bolster its special forces in Syria, Russian Foreign Ministry spokeswoman Maria Zakharova said on Wednesday.

President Barack Obama announced on Monday the biggest expansion of U.S. ground troops in Syria since its civil war began.

The deployment of up to 250 Special Forces soldiers increases U.S. forces in Syria roughly sixfold and is aimed at helping militia fighters who have clawed back territory from Islamic State militants in a string of victories.

(Reporting by Andrew Osborn; Writing by Dmitry Solovyov; Editing by Denis Pinchuk)