(CNSNews.com) – As the U.S. looks towards securing a strong U.N. Security Council resolution responding to North Korea’s missile launch, Pyongyang on Sunday ratcheted up the rhetoric, warning of a nuclear conflict and “another world war.”

North Korea’s foreign ministry also signaled that the U.S. could expect more “gift packages” of various types, feeding into concerns that the regime may be planning more launches – or possibly the first nuclear test of the Trump era.

The latest statements came after live-fire drills on Friday involving U.S. and South Korean aircraft, including two U.S. Air Force B-1B Lancer heavy bombers which flew to the peninsula from Guam.

Accusing the U.S. of “playing with fire,” the Rodong Sinmun regime organ said that “a simple misjudgment or mistake may lead to the outbreak of a nuclear war and that, in turn, is sure to lead to a new world war.”

“The U.S. saying it will regularly deploy strategic bombers to the Korean peninsula is the same as a crazy act of playing with fire on top of an ammunitions locker,” it added.

U.S. Pacific Command linked the deployment of the supersonic B-1B Lancers directly to the July 4 intercontinental ballistic missile (ICBM) launch, and said it was “part of the continuing demonstration of the ironclad U.S. commitment to our allies against the growing threat from North Korea’s ballistic missile and nuclear programs.”

“Let me be clear,” said Pacific Air Forces commander Gen. Terrence O’ Shaughnessy. “If called upon we are trained, equipped and ready to unleash the full lethal capability of our allied air forces.”

En route back to Guam, the two bombers flew with fighter jets from the Japanese Air Self-Defense Force, in a show of support for the other U.S. treaty ally in the region within North Korean missile range.

U.S.-South Korea joint military exercises have been conducted for decade, but Pyongyang’s condemnation of them has become more vehement in recent times. In opposing a U.S.-led push for tough new U.N. Security Council sanctions after the ICBM launch, China and Russia are proposing, as an alternative, a deal that would include a freeze on such joint maneuvers.

‘Capability to strike the very heart of the US’

U.S. Ambassador to the U.N. Nikki Haley reiterated Sunday that the U.S. will not accept a “watered-down” resolution in New York.

“It will be very telling as to whether China works with us, which we are hoping that they will,” she said on CBS’s “Face the Nation.”

Haley said the U.S. would also know within days “whether Russia is going to stand with North Korea and … just oppose us for the sake of opposing us, or whether everybody is going to say once and for all to North Korea: ‘Stop, this is reckless, it’s irresponsible and we’re not going to take it anymore.’”

China is North Korea’s main trading partner and has for years been its number-one defender in the Security Council. In response to questions, Haley did not rule out the possibility that China’s trading relationship with the U.S. could be imperiled.

“We do a lot of trade with a lot of countries,” she said. “If there is a country that we don’t think is looking out for our security and looking out for our confidence in that, then yes – that [sanctions] is one of the ammunition options we have on the table.”

“We need the pressure on North Korea and China has the ability to do it,” Haley said. “They know that, we know that, and we need to see some more action going accordingly. And I think the resolution is going to be a really big test on that.”

North Korea’s foreign ministry said in a statement Friday the ICBM launch was intended to send a message specifically to one country – the United States.

“The test-fire of the inter-continental ballistic rocket conducted by the DPRK this time is a ‘gift package’ addressed to none other than the U.S.,” it said, using the acronym for the Democratic People’s Republic of Korea, the Stalinist state’s formal name.

Describing its nuclear and missile capabilities as a deterrent against U.S. aggression, the ministry said that “now that the DPRK’s capability to strike the very heart of the U.S. at any given time has been physically proved, the U.S. would find it more difficult to dare attack the DPRK.”

The statement ended with a promise of more to come: “The U.S. will receive more ‘gift packages’ of different sizes from the DPRK in endless succession.”

Analysts have been keeping as close as possible a watch on North Korea’s Punggye-ri nuclear test site, where activity detected by U.S. surveillance satellites last month stoked speculation that the regime may be preparing to conduct what would be a sixth nuclear test.

However 38 North, a specialist website, reports that there has been no new observable activity at Punggye-ri since then, based on commercial satellite imagery.

“At the same time, there does appear to have been an overall clean-up of the facility, giving the impression of an unusually well-maintained site at a high state of readiness to host another underground nuclear test on short notice,” it said.

Punggye-ri is the site of all five previous nuclear tests – in 2006, 2009, 2013, and in January and September of last year.