"The United States will also have to undertake careful deliberations about the fate of the planned North Korea-US summit in light of this provocative military ruckus jointly conducted with the South Korean authorities".
"Nothing has changed on North Korea that we know of", Trump said during a photo opportunity with NATO Secretary General Jens Stoltenberg.
"The president is very used to and ready for tough negotiations", she continued.
The current uncertainty comes at a time when Trump's withdrawal from the Iran nuclear deal has drawn criticism internationally and moving the US embassy in Israel to Jerusalem has fueled deadly violence on the Israel-Gaza border.
Trump put North Korea back on the list of state sponsors in November, after a nine-year hiatus, allowing the United States to impose more economic sanctions against Pyongyang over its nuclear and missile programs.
North Korea may well be bluffing in its threat to the USA, but setting expectations for what it wants from the June 12th summit is crucial for the Trump administration as it prepares the ground for Singapore.
"If they don't, that's OK too, and we'll continue with our campaign of maximum pressure". North Korea abruptly canceled high-level talks scheduled for Wednesday with the South, citing the current joint U.S. "We'll have to see what happens", he said.
On Wednesday, Bolton brushed aside the North Korean remarks against him and said odds were still in favor of the summit going ahead.
Robert Kelly, a Koreas analyst from Pusan National University, told Al Jazeera that North Korea may be playing a game of political brinksmanship.
Sanders appeared reluctant to endorse the Libya model that the hawkish Bolton has touted, most recently on USA television news programmes on Sunday.
Some suggested that Mr. Trump needed to rein in Mr. Bolton - a point the North Korean official, Mr. Kim, appeared to be making in his statement. "He is going to run this the way he sees fit". "We're 100 percent confident. he's the best negotiator".
Negotiations between North Korea and the United States have started off with major concessions on the side of the Kim regime. "In Libya we decimated that country".
In the past, Pyongyang has demanded the withdrawal of USA troops stationed in the South, and an end to Washington's nuclear umbrella over its ally. Most recently, three Americans being detained in North Korean prison camps have been released and flown home to the United States. North Korea has given concessions by releasing US detainees and setting a date for the dismantling of its nuclear test site.
Kim said North Korea will not be interested in the Trump-Kim summit if Washington tries "to push us unilaterally into a corner and force us to give up nukes". Pyongyang has also taken strong exceptions to military drills between the USA and South Korea.
"Ukraine in 1994 gave up two thousand nuclear weapons in exchange for a guarantee by Russian Federation, the United States, and the United Kingdom of its territorial integrity and it's lost half its country". -South Korea military drills now being staged on the peninsula. "They have historically made unreasonable demands ahead of summit talks and then threatened to walk away if they don't get what they want", he said.