Washington - President Donald Trump says that "talking is not the answer" when it comes to North Korea. And he's claiming the US has been paying North Koreans what he calls "extortion money" for decades."The US has been talking to North Korea, and paying them extortion money, for 25 years," Trump tweeted on Wednesday morning, adding: "Talking is not the answer!"The tweet comes on the heels of the North's recent missile test over Japan, a close American ally.Trump's tweet did not spell out what he meant by "extortion" in the current standoff over North Korea's nuclear programme, and the White House did not immediately respond to questions.North Korea has in the past temporarily halted nuclear development when the US and others provided food aid or other types of compensation. But the North hasn't been making such demands, at least publicly, since Trump came into office. Instead, it has been focused on finishing its decades-long effort to master the technology for fitting a nuclear warhead on a missile that can striking the US mainland, calling such capability essential for its national defence.Trump's assessment about the need for dialogue also appears at odds with his top diplomat, Secretary of State Rex Tillerson, who had in recent weeks been softening the conditions for a possible, formal dialogue with Pyongyang. The US also has been maintaining a diplomatic back channel with North Korea.Trump offered a surprisingly subdued response to Pyongyang's latest missile test on Tuesday, avoiding a repeat of his bombastic warnings earlier this month of a potential military confrontation.