BOSTON — Russia and Iran have obtained U.S. voting registration information, the government’s national intelligence director said at a rare news conference Wednesday night. John Ratcliffe, the intelligence director, and FBI Director Chris Wray say the U.S. will impose costs on any foreign countries interfering in the 2020 U.S. election. Democratic voters in at least four battleground states including Florida and Pennsylvania received threatening emails, falsely purporting to be from the far-right group Proud Boys, that warned “we will come after you” if the recipients didn’t vote for President Donald Trump. The voter-intimidation operation apparently used email addresses obtained from state voter registration lists, which include party affiliation and home addresses and can include email addresses and phone numbers.