JUDY WOODRUFF:

We will take a closer look at the implications of May's move later in the program.

Police in France say they have broken up an imminent attack aimed at that country's presidential election. They arrested two suspects today in the port city of Marseille, and recovered guns and explosives. Prosecutors accuse the pair of being Islamic extremists. The first round of voting in France's presidential race begins on Sunday.

In Turkey, the main opposition party is formally asking to annul Sunday's referendum that expanded the powers of President Recep Tayyip Erdogan. Hundreds of people waited outside the electoral board's headquarters today to file petitions against the vote. They say accepting ballots without an official stamp was illegal.

Separately, the White House defended President Trump's congratulatory call to Erdogan, arguing that he is an ally in the fight against terrorism.

Vice President Mike Pence moved on from South Korea to Japan today, and again pressed the U.S. case against North Korea. In Tokyo, Mr. Pence said the U.S. will not relent until the Korean Peninsula is free of nuclear weapons. And he told Japanese Prime Minister Shinzo Abe that American support is unwavering.