Chief Cabinet Secretary Yoshihide Suga repeated that it was vital for North Korea to take concrete steps toward complete, verifiable and irreversible dismantlement of all its weapons of mass destruction and missiles.
In an executive order, the president extended for one year the so-called "national emergency" with respect to the nuclear-armed nation, re-authorizing economic restrictions against it.
United States president Donald Trump on Friday cited "an unusual and extraordinary threat" from North Korea's nuclear arsenal to extend sanctions on Kim Jong-un's regime, despite touting the success of a historic summit earlier this month.
"Just landed - a long trip, but everybody can now feel much safer than the day I took office".
President Trump is condemning the mainstream media for the negative coverage of the joint summit with North Korea.
"We got back our great fallen heroes, the remains sent back today, already 200 got sent back", Trump told a crowd of supporters during a rally in Duluth, Minnesota.
Trump called the exercises "war games" and agreed with North Korea's assertions that they were "provocative".
The official said it was hard to tell exactly how many would be United States troops as they would require forensic testing to determine their identity. According to the Pentagon, North Korean officials have indicated in the past they have the remains of as many as 200 USA troops. "And the big thing is it will be a total denuclearization, which has already started taking place".
It follows the decision earlier this week to suspend a major joint military exercise between the US and South Korea that had been planned for August.
Japan has chose to halt evacuation drills to prepare for a potential North Korean missile attack as tensions had eased following a historic summit between the leaders of the United States and North Korea, Kyodo news agency reported on Thursday. "Saying the North Korea problem is solved doesn't make it so".
Trump and Secretary of State Mike Pompeo have said that all US sanctions will remain in force for now.
"The report of President Trump's own administration completely undercuts his statements over the last few weeks", said the Senate's top Democrat, Chuck Schumer. Trump, who held a landmark meeting with Kim on June 12, said he was extending it by another year.
"To support implementing the outcomes of the Singapore Summit, and in coordination with our Republic of Korea ally, Secretary Mattis has indefinitely suspended select exercises", Pentagon spokeswoman Dana White said in a statement.