<br /> U.S. efforts to sustain and possibly intensify its “maximum pressure” campaign on North Korea are entering a perilous phase. This as a potential breakdown in diplomacy with Pyongyang raises fears that China may loosen its enforcement of international sanctions.<br />With the fate of a summit between President Donald Trump and North Korean leader Kim Jong Un in limbo, U.S. officials have suggested Washington may pursue fresh sanctions on Pyongyang over its nuclear program. <br />
