(CNN) North Korea has lashed out at the US after it conducted joint bomber drills with the South Korean air force, accusing it of reckless provocation.
Pyongyang described the exercise, which involved two B1-B bombers, as a "nuclear bomb-dropping drill" that made nuclear war more likely. North Korean state media described US President Donald Trump as a "warmonger".
The outburst came as the officials said that a controversial US missile defense system was up and running in South Korea -- albeit in a limited capacity. That announcement came a week before presidential elections in South Korea that are expected to bring in a government critical of the Terminal High Altitude Area Defense system, known as THAAD.
The latest belligerent statement from Pyongyang was a response to the deployment of two US bombers over the Korean peninsula on Monday -- as part of a joint drill with South Korea and Japan's air forces.
South Korean Defense Ministry spokesman Moon Sang-gyun told a briefing Tuesday that the deployment was part of an effort to "respond to North Korea's nuclear missile threat and to deter North Korea's provocations."
North Korean state news agency KCNA denounced the exercise in typically bombastic terms. "The reckless military provocation is pushing the situation on the Korean peninsula closer to the brink of nuclear war," KCNA said.
It claimed that "Trump and other US warmongers" were determined to make a preemptive nuclear strike on North Korea. Trump said on Monday that he might be willing to meet North Korean leader Kim Jong Un "under the right circumstances
The latest rhetorical tussle came amid increasing military activity around the Korean peninsula. A US official said the the THAAD missile system was now capable of shooting down a North Korean missile,although it was operating in a limited capacity. The official said thatthe US hopes to install additional units to increase coverage over South Korea.
THAAD was deployed to South Korea by the US in response to North Korea's increased missile and nuclear tests, but the defense system has drawn sharp opposition from China and Russia, whose territory is within the system's range.
China again expressed its displeasure Tuesday, urging both sides to "stop the deployment immediately."
"We will also firmly take necessary measures to safeguard our own interests," added Chinese Foreign Ministry spokesman Geng Shuang.
THAAD is not expected to be fully operational until the end of the year, but US and South Korean officials publicly stressed the need to speed up the deployment of the technology as tensions mounted with Pyongyang.
South Korean Defense Ministry spokesman Moon Sang-kyun said at a briefing last week that equipment, including launchers, combat control stations and radar, had been deployed to the site in North Gyeongsang province and would be imminently operational.
"These things are now in place, so you can connect them to get the operational capability from early on -- that's what 'within days' means," he said.
Moon Jae-in, the frontrunner in South Korea's Presidential election which takes place on May 9, has expressed skepticism over THAAD.
Throughout his campaign he's called for its deployment to be decided by the next government.
Speaking to South Korean radio station BBS FM on Tuesday, Moon said the deployment was "not a done deal yet," and should be based on public consultation and a vote in the country's National Assembly.
Moon's Democratic Party is currently 20 points clear of its nearest rival, according to the most recent Gallup Korea daily opinion poll. Around 40% of voters surveyed said they favored Moon, compared with 24% for centrist candidate Ahn Cheol-soo.
THAAD is designed to shoot down short- and medium-range ballistic missiles in the latter stages of their flight as they plunge toward their targets.
While this means it cannot act against the type of intermediate-range missiles North Korea has been testing in recent months, THAAD also includes a sophisticated radar that will fit into an overlapping series of US missile defense systems, including Aegis warships operating in the Pacific and Patriot missile batteries deployed to Japan.
The radar could provide critical early tracking data to these missile interception systems, as well as those protecting Guam, the closest US territory to North Korea.