Whenever the President shall have issued a proclamation under the authority of section
441
(a) of this title, it shall thereafter be unlawful for any person within the United States to purchase, sell, or exchange bonds, securities, or other obligations of the government of any state named in such proclamation, or of any political subdivision of any such state, or of any person acting for or on behalf of the government of any such state, or political subdivision thereof, issued after the date of such proclamation, or to make any loan or extend any credit (other than necessary credits accruing in connection with the transmission of telegraph, cable, wireless and telephone services) to any such government, political subdivision, or person. The provisions of this subsection shall also apply to the sale by any person within the United States to any person in a state named in any such proclamation of any articles or materials listed in a proclamation referred to in or issued under the authority of section
452
(i) of this title.