The Biden administration said Monday it's looking at “additional actions” that the United Nations might take to respond to North Korea’s recent missile tests. U.S. Ambassador to the United Nations Linda Thomas-Greenfield wasn’t specific about what those actions might entail, but noted that the UN Security Council had met last week and renewed the mandate of experts who monitor sanctions against the North. The council is also expected to hold closed-door discussions on North Korea on Tuesday.*
*U.S. eyes additional UN action on N. Korea after missile tests, by Matthew Lee, Associated Press, March 29, 2021, 2:18 p.m; https://lasvegassun.com/news/2021/mar/29/us-eyes-additional-un-action-on-n-korea-after-miss/
It's unlikely the US will get a binding UN resolution to go beyond UN res 2397 which authorized sanctions for long range ballistic missiles and nuclear tests by North Korea. The general proscription against North Korean ballistic missile launches in UN resolution 2397, was not entirely supported by an enforcement mechanism. In other words, there is wiggle room over shorter ranged missiles for North Korea. Evidently the Security Council compromised on the resolution's language in 2017. So a new resolution would be required. They probably won't get it from the Security Council because both Russia and China disagree with the US approach to the negotiating process. Resolution 2397 in paragraph 26 refers to the Joint Statement of Sep 9, 2005, in the fourth round of the Six Party Talks, which reads:
5) The six parties agreed to take coordinated steps to implement the aforementioned consensus in a phased manner in line with the principle of "commitment for commitment, action for action."
Since Singapore the US abandoned this "phased" approach emphasizing reciprocity and adopted the so called "one bundle" approach, aka "the Libyan Approach," and "the all or nothing approach." Only Japan of the six parties agrees with this US approach.
(Picture source Channel A Top Ten News 5.7.2019) North Korea tactical guided missile left. South Korean Hyunmoo tactical guided missile right. Both solid fueled.
Resolutions by the General Assembly are generally not binding. The US could try to get a General Assembly resolution, and then implement some sort of escalatory move unilaterally or in conjunction with it's closest allies. The AP News report cited above recites the boilerplate US language emphasizing how unified Japan and South Korea are with the US view of the North Korean situation, However, it isn't true that the current South Korean administration agrees with the US negotiating approach. They only agree with the goal, "denuclearization of the Korean peninsula." At the same time, we have the continuing development of the South Korean Hyunmoo ballistic missile, which is ostensibly a short range tactical missile. Read the Ankit Panda report referenced below on South Korean missile development below to see the difficulties of adopting a new approach to North Korean short range missile testing.
The Hyunmoo-4 is an 800-kilometer-range system that entered testing for the first time earlier in 2020. Moon applauded it recently for exhibiting “close to the world’s heaviest warhead weight,” making full use of the 2017 update to the missile guidelines. While this missile is thought to feature a 2,000-kilogram payload, if it were to be launched with a payload half that weight, the Hyunmoo-4 would perform as a medium-range missile (using the U.S. government definition of missiles with ranges between 1,000 and 3,000 kilometers).*
*Solid Ambitions: The US South Korea Missile Guidelines and Space Launchers, Ankit Panda, Carnegie Endowment for International Peace, Aug 25, 2020; https://carnegieendowment.org/2020/08/25/solid-ambitions-u.s.-south-korea-missile-guidelines-and-space-launchers-pub-82557
Here's an account of an official North Korean reaction by Military Commission Vice Chairman, Ri Pyong-chol, to President Biden's statement regarding the recent North Korean short range missile tests from Hankyoreh in South Korea:
Ri's statement functioned as a rebuttal to Biden's statement in his press conference on Thursday that North Korea's launch of ballistic missiles was a violation of a UN Security Council resolution and his warning that "if they choose to escalate, we will respond accordingly."
Ri said that Biden had attacked "the regular [test launch and] exercise of our state's right to self-defence as the violation of UN' resolutions,'" describing this as an "an undisguised encroachment on our state's right to self-defence and [a] provocation to it."*
* N. Korea, US dialogue won't resume anytime soon, Hankyoreh, Mar. 29, 2021; By Gil Yun-hyung; http://english.hani.co.kr/arti/english_edition/e_northkorea/988668.html
Is the Biden administration taking a more constricted view of these North Korean short range missile tests than the Trump administration? The prior president who regarded them as "no big deal," was actually expressing a view consistent with the actual intent of the UN resolution 2397. In light of South Korean missile developments is it possible to take a more stringent position? The US, itself, has expressed plans to deploy offensive missiles systems in East Asia now that it is no longer constrained by the INF Treaty with Russia.
Under the current circumstances of worsening US relations with China and Russia, it is quite unrealistic for the Biden administration to expect Chinese or Russian assistance to bring North Korea to the table while the US "takes a hostile approach." This approach can be described as the same hardline approach the former US administration had taken at the Hanoi summit and thereafter, insisting on an ever increasing list of demands on North Korea with no evidence of a phased reciprocal exchange of commitments as part of a trust building process. Why would the Chinese reward the US posture? When the US team of Blinken and Austin were in South Korea recently, the Defense Secretary complained that the conditions at the US Seongju THAAD installation were inadequate and unacceptable to US forces. This appears to be an expression of US intent to make the THAAD base a permanent installation in South Korea, something to which the Chinese had previously protested to South Korea as a matter of Chinese national security. Perhaps the South Koreans could be forgiven for wishing it was a temporary facility.