US President Donald Trump declined to reveal how he plans to stop North Korean leader Kim Jong Un from developing his nuclear arsenal, but experts said unilateral US action against North Korea could entail three approaches.
Can the North Korean issue be resolved by talking - possibly over a hamburger? That was what President Donald Trump suggested during his campaign.
"I don't think a burger and fries is going to solve this one," Hoover Institution research fellow Lanhee Chan told CNN, adding that dialogue would not work overnight.
Pyongyang may be willing to suspend its nuclear and missile programmes if Washington addresses its security concerns, said Dr Leon Sigal, director of the North-east Asia Cooperative Security Project at the Social Science Research Council in New York. "The only way out of Trump's predicament is acceptance - resume talks with North Korea, the sooner the better, to probe whether it is willing to suspend arming," he wrote in an article for CNN.
2 TIGHTEN THE SCREWS
The United States should go after Chinese banks and firms that may be helping North Korea, said Mr Anthony Ruggiero, a senior fellow at the Foundation for Defence of Democracies.
He told CNN: "Trump needs to unleash the Treasury Department to investigate Chinese companies and banks, tell them it is not going to be allowed, and fine them."
Last Friday, the US imposed sanctions on 11 North Koreans and one North Korean company for their links to the country's weapons programme and violating United Nations sanctions.
But others say sanctions are not the answer.
"The bottom line is that the last thing they are going to cut is the military," associate professor of Chinese studies John Delury, from Yonsei University in South Korea, told CNN.
3 MILITARY ACTION
In Asia last month, Secretary of State Rex Tillerson said the US would consider military action against North Korea if provoked. Any US strike on the country can exact a high toll on South Korea, say analysts.
In a report last year, geopolitical analysis group Stratfor said the US could take out North Korea in a first strike that could rain over 600 cruise missiles and smart bombs on North Korean targets. But Pyongyang could fire a nuclear weapon towards South Korea or Japan.
Another option is to use US warships to shoot down North Korean missile tests, said Dr Peter Layton, visiting fellow at the Griffith Asia Institute in Australia. A simple option could be a blockade of ships leaving and entering North Korea, he added.
Covert raids by special forces in North Korea would risk exposing US troops to capture and may be ineffective without elite or popular resistance against the North Korean regime, say experts.