After , no construction of permanent housing may be begun under subchapter IX of this chapter. After , (a) no mortgage may be insured under title IX of the National Housing Act, as amended [ et seq.] (except (i) pursuant to a commitment to insure issued on or before such date or (ii) after , and until , during such period, or for such project or projects, as the President may designate hereunder or (iii) pursuant to a commitment to insure issued pursuant to the preceding clause (ii)), (b) no agreement may be made to extend assistance for the provision of community facilities or services under subchapter IX of this chapter, and no construction of temporary housing or community facilities by the United States may be begun under such subchapter, except after , and until , during such period, or for such project or projects, as the President may designate hereunder: , That to the extent necessary to assure the adequate completion of any facilities for which prior agreements have been made under subchapter IX, the Secretary of Housing and Urban Development may, at any time after , enter into amendatory agreements under such subchapter involving the expenditure of additional Federal funds within the balance available therefor on or before such date, (c) no loan may be made or obligations purchased by the Secretary of Housing and Urban Development under (except pursuant to a commitment issued on or before , or to refinance an existing loan or existing obligations held under such section by said Secretary on ).12 U.S.C. 1750section 1701g–1 of title 12June 30, 19531953-06-30July 31, 19541954-07-31July 31, 19541954-07-31August 1, 19551955-08-01July 31, 19541954-07-31August 1, 19551955-08-01July 31, 19541954-07-31June 30, 19531953-06-30June 30, 19531953-06-30Provided