JERUSALEM — Under intense pressure from President Trump, Prime Minister Benjamin Netanyahu’s government on Thursday barred two members of the United States Congress from entering Israel for an official visit, reversing a previous decision to admit two of the president’s most outspoken critics.

But on Friday, Israel said that one of the congresswomen, Representative Rashida Tlaib, could enter on humanitarian grounds so that she could see her 90-year-old grandmother, after she promised to “not promote boycotts” during her stay.

By enlisting a foreign power to take action against two American citizens, let alone elected members of Congress, Mr. Trump crossed a line that other presidents have not, in effect exporting his partisan battles beyond the country’s borders. And he demonstrated the lengths that he will go to to target his domestic opponents, in this case two of the congresswomen of color he has sought to make the face of the Democratic Party heading into his re-election campaign.

[Israel Says Rashida Tlaib Can Visit to See Her Grandmother]

In initially blocking the visits of the two Democratic congresswomen — Representatives Tlaib of Michigan and Ilhan Omar of Minnesota — who are both Muslim, Mr. Netanyahu cited their support for boycotting Israel, acceding to the wishes of the American president, who declared on Twitter shortly before Israel’s announcement that letting them in would “show great weakness.”