Assistant Secretary of State for East Asian and Pacific Affairs Danny Russel stated to Reuters on Tuesday that, similar to adjusting a medicine regimen, the dosage of sanctions can be increased if the desired effects are not achieved. Russel mentioned the potential for new sanctions by the UN Security Council, the United States, or a coalition of countries from the European Union and Southeast Asia. North Korea's recent nuclear test and rocket launch led to enhanced UN sanctions to cut off funding for its nuclear weapons program. There are concerns about a possible fifth nuclear test by North Korea before a ruling party congress in early May, following a failed missile test. Estimates suggest there may be up to 150,000 North Korean workers abroad, mostly in China and Russia, sending back around $900 million annually. North Koreans are known to work in various fields abroad such as restaurants, construction sites, and as doctors. The success of current or any new sanctions relies heavily on their full implementation by China, North Korea's neighbor and largest trading partner. US officials and analysts emphasize the importance of China's cooperation in enforcing sanctions. Chinese Foreign Ministry spokeswoman Hua Chunying urged all parties to avoid escalating tensions and to remain calm in order to resume talks. She declined to comment on whether China would support tougher sanctions if North Korea conducted another nuclear test. US and its allies South Korea and Japan could also take defensive actions in response to such a test, according to Russel. He mentioned that as the threat increases, our defensive capabilities should also adapt accordingly. He emphasized that there is a diplomatic option available to North Korea by reopening negotiations to limit its nuclear program. South Korean Unification Ministry spokesman Jeong Joon-hee suggested focusing more on sanctions rather than dialogue in response to North Korea's potential provocations. Russel discussed potential responses to a fifth nuclear test by North Korea, acknowledging that sanctions have not effectively deterred the country since its first nuclear test in 2006. He clarified that no decisions have been made yet regarding a response to a future event. US General Vincent Brooks, nominated by President Barack Obama to lead American forces in South Korea, stated that China is frustrated with North Korea's behavior, particularly its nuclear advancements, but is hesitant to apply pressure that could jeopardize Kim Jong Un's regime. Brooks also noted that Kim Jong Un appears to be more daring, arrogant, and impulsive compared to his father, Kim Jong Il. He emphasized that Kim has been more assertive in disregarding international concerns while advancing North Korea's nuclear program. Assistant Secretary of State Russel mentioned that it will take time to assess the effectiveness of the latest sanctions, but acknowledged that Beijing has shifted towards applying pressure on North Korea after exhausting diplomatic efforts. Russel added that there is now a push for sustained pressure on North Korea, which has not been seen before. China's strong economic influence on North Korea has led to a new situation, according to Frank Jannuzi. He doubts that China is truly willing to exert significant pressure on North Korea due to concerns about potential negative consequences such as conflict, refugees, and turmoil.