US Defence Secretary James Mattis (left) and Chairman of the Joint Chiefs of Staff Joseph Dunford are seen after briefing US senators.
The statement added that Pyongyang's pursuit of nuclear weapons is "an urgent national security threat and top foreign policy priority".
Wednesday's briefings will focus on three key issues related to North Korea's nuclear program: intelligence about the North's capabilities; US response options, including military ones; and how to get China and other countries to enforce existing economic sanctions on Pyongyang, along with ideas for new penalties.
The two sides shared the view that military clashes on the peninsula must be avoided, Wu told reporters after the meeting. A USA pre-emptive attack isn't likely, American officials have said, and the Trump White House has settled on a strategy of increasing pressure on North Korea with the help of China.
The drill came instead of a nuclear test or the launch of a long-range missile as feared amid pressure from the United States and China, its sole major ally which has been irritated by Pyongyang's weapons development. Cardin said the US needs to plan for contingencies as Kim Jong Un is an unpredictable leader but there's no "pretty military solution".
THAAD "will be operational in the coming days and able to better defend South Korea against the growing North Korean threat", Admiral Harry Harris, who heads Pacific Command, told politicians in Washington.
"That's my fault on the confusion and I'll take the hit for it", Harris said. USA military exercises and deployments in the region do get some press coverage but are seldom emphasized (in the absence of a snafu like the recent wrong-way aircraft carrier strike group). Later in the day, the same military briefers will travel to the Capitol tonight to fill in members of the House.
The countries want to include the clause in a United Nations Security Council resolution draft, among other measures such as prohibiting North Korea from exporting its labour.
Addressing security challenges in the Indo-Asia-Pacific region, the commander noted how North Korea threatened Australia in the past week with a nuclear strike.
"China will resolutely take necessary steps to defend its interests", he said yesterday, without elaborating.
"I didn't hear anything new because I have been heavily briefed before", said Senator John McCain, the Republican chairman of the Senate Armed Services Committee.
Democratic Rep. Adam Schiff of California agreed.
"We simply do not have a comprehensive or precise picture of the North Korean nuclear program, especially when it comes to the number of weapons and delivery vehicles", it says. "That's all it is", Toner said.
Policy updates by administration officials are usually given to United States lawmakers in congressional rooms at Capital Hill in Washington, leading some commentators to suggest the exercise was merely a photo-op for President Trump. Ted Cruz told Fox News following the meeting.
The statement said Seoul and Washington have been pushing to get THAAD working soon to cope with North Korea's advancing nuclear and missile threats.
South Korea said in a statement on Wednesday that unspecified parts of THAAD were deployed. It said it would win in a "death-defying struggle against the US imperialists".
The Post reports that Japan's civil-defense website is experiencing a huge spike in traffic and features frequently asked questions about North Korean missile strikes.
Large components of the U.S. THAAD system began landing in South Korea early last month, under an agreement that was reached last July.
Global tensions over the North Korea threat remain high.
He said China and the U.S. have shared interest on the Korean Peninsula, where both want to see continued stability and progress toward denuclearization.
"We should encourage China and be appreciative of what they are doing with regards to North Korea and we should also be willing to criticize them for their aggressiveness and coerciveness in the South China Sea", Harris said. That was a reference to USA and South Korean war games.
The plan to deploy THAAD has angered North Korea as well as China, which sees the system as a security threat despite reassurances that the system is purely defensive.
In Beijing, Chinese foreign ministry spokesman Geng Shuang said the THAAD system's deployment would "disrupt the regional strategic balance and further aggravate the tension on the peninsula".