Prior to the Japanese leader's departure from Tokyo's Haneda airport, Abe said he wanted to exchange candid views while in Iran and help ease rising tensions.
The 39 billion pounds represents outstanding British liabilities to the EU, which would be paid over a number of years according to the withdrawal agreement negotiated by May.
In a statement, Panelo defended President Rodrigo Duterte's crackdown on illegal drugs, which the UN says has led to over 27,000 deaths since the campaign began in June 2016.
The nation currently uses 141 litres per person each day - about enough for two typical eight-minute U.S. showers, according to Harvard University statistics.