Shannon Van Sant | KALW

Shannon Van Sant

Updated at 3:20 a.m. Monday

The United Kingdom is trying to defuse an escalating standoff with Iran just days before Britain's ruling Conservative Party announces the successor to Theresa May, who is resigning.

Some 160,000 members of the Tory Party have until today to return their ballots selecting a new leader. The winner, to be announced on Tuesday, is expected to be Boris Johnson.

President Trump is in Japan for the first official state visit since Japanese Emperor Naruhito assumed the throne.

The president and first lady Melania Trump have already dined with Japanese business leaders and will attend a sumo wrestling match, at which Trump will present the winner with a trophy called the "President's Cup."

Emperor Naruhito and his Harvard-educated wife, Empress Masako, will host an imperial state banquet for Trump. The president's trip will also include a visit to a naval base and bilateral meeting with Japanese Prime Minister Shinzo Abe.