Tribe that assumes a responsibility, including a financial responsibility, under paragraph (1) shall be solely responsible and solely liable for carrying out, in lieu of the Secretary concerned, the responsibility assumed under that paragraph until the date on which a relevant termination is carried out under subsection (g). (C) Environmental review A State or Indian Tribe that assumes a responsibility under paragraph (1) shall comply with the environmental review procedures under parts 1500–1508 of title 40, Code of Federal Regulations (or successor regulations), and the regulations of the Secretary concerned. (3) Federal responsibility Any responsibility of the Secretary concerned described in paragraph (1) that is not explicitly assumed by a State or Indian Tribe under that paragraph shall remain the responsibility of the Secretary concerned. (c) Offer and notification A State or Indian Tribe that intends to offer to enter into a memorandum of understanding under this section shall provide to the Secretary concerned notice of the intent of the State or Indian Tribe at least 90 days before the date on which the State or Indian Tribe submits a formal written offer to the Secretary concerned. (d) Tribal consultation Not later than 90 days after the date on which the Secretary concerned enters into a memorandum of understanding under this section with a State, the Secretary concerned shall initiate consultation with relevant Indian Tribes. (e) Memorandum of understanding A memorandum of understanding entered into under this section shall— (1) be executed by the Governor or the Governor’s designee, in the case of a State, or by the officer designated by the governing body of an Indian Tribe, in the case of an Indian Tribe