Japan plans to maintain maximum pressure on North Korea to make it abandon its nuclear weapons and missile programs in close coordination with the United States, government officials said Sunday.

The government scrambled to gather information to help it understand what is behind U.S. President Donald Trump's recent back and forth on the potential summit with North Korean leader Kim Jong Un in Singapore.

Over the weekend Trump and Kim, respectively, expressed their readiness to meet on June 12 as originally planned, after days of conflicting signals from both sides.