May 11 (UPI) -- The United States must be willing to negotiate with North Korea before Pyongyang conducts its sixth nuclear test, a Chinese analyst said Wednesday.
Liu Ming, a Korea security expert at the Shanghai Academy of Social Sciences, told Russia's Tass news agency the next test could occur in the near future, possibly in May.
"Once a sixth nuclear test has been carried out, the window of opportunity to solve the North Korean problem will almost be closed," Liu said. "There won't be many opportunities to solve the problem using diplomatic means."
Liu added all issues between "the United States and North Korea are centered around contradictions," possibly referring to the mixed approach to North Korea by U.S. President Donald Trump, and unmet expectations following threats from Pyongyang.
"Under the current circumstances, it does not make sense to return to the resumption of six-party talks," Liu said. "First, the United States and North Korea must negotiate directly."
The analyst also said Pyongyang could conduct its next test within the month.
"Just because April went by without a nuclear test does not mean there won't be one in May," he said.
Liu also said tensions are likely to continue in June.
North Korea has completed all preparations for its next test and is biding time, according to the analyst.
Trump administration officials have said they would not negotiate with North Korea unless the country agrees to take steps toward denuclearization.
Former U.S. officials met with North Korean diplomat Choi Sun Hee this week in Oslo, for a round of informal talks.
Former U.S. Pacific Commander Adm. William Fallon, former U.S. Ambassador to the United Nations Thomas Pickering, and Robert J. Einhorn, former special adviser for nonproliferation and arms control at the U.S. Department of State, were in attendance, according to Yonhap.
Increased economic pressure from China and a growing rift with Beijing may have influenced North Korea's decision so far to stay away from nuclear testing.