The Trump administration is hopeful its summit with North Korea will go ahead, despite threats of cancellation.
A White House spokesperson said the US president remained ready.
Hours earlier, North Korea released an angry statement saying it might pull out of the meeting if the US insisted it gave up its nuclear weapons.
The highly anticipated meeting between Mr Trump and North Korea's Kim Jong-un is due to take place on 12 June.
"The president is ready if the meeting takes place," said White House spokesperson Sarah Sanders. "If it doesn't, we'll continue the maximum pressure campaign that's been ongoing."
Mr Trump has not yet commented on the latest development.
