US Secretary of State Rex Tillerson said on Tuesday that Washington is ready to talk anytime with Pyongyang, with no preconditions attached.

"From the diplomatic side, we're ready to talk anytime North Korea would like to talk, and we're ready to have the first meeting without precondition," Tillerson said in a speech to Washington's Atlantic Council think tank.

Observers noted that Tillerson's remarks came nearly two weeks after the Democratic People's Republic of Korea launched an intercontinental ballistic missile on Nov 29, which it claimed was capable of striking the US mainland.

While Tillerson spoke, the US, South Korea and Japan were conducting a two-day maritime exercise started on Monday to track ballistic missiles over waters near the Korean Peninsula and Japan.

Tillerson reiterated Washington's position that it cannot accept a nuclear-armed DPRK. He said US President Donald Trump encouraged diplomatic efforts, and the US was "ready to talk anytime they're ready to talk".

"It's not realistic to say we're only going to talk if you come to the table ready to give up your program," he said. "They have too much invested in it. The president is very realistic about that as well."

But he said there would have to be a period of quiet without devices tested in the middle of the talks to ensure productive discussion.

"Let's just meet and let's – we can talk about the weather if you want. But can we at least sit down and see each other face to face? And then we can begin to lay out a map, a roadmap of what we might be willing to work towards," Tillerson said.

Tillerson, however, made it clear that the diplomatic effort has to be backed up with a credible military alternative.

"There are multiple military options that have been developed to deal with a failure on my part," he said. "That's why I say we're going to work hard to not fail. And the president wants that, and he has encouraged our diplomatic efforts."

In his speech, Tillerson also said the US and China are searching for what will define their bilateral relationship for the next half century, and cabinet-level dialogues would help this search.

"I think both of us, the US and China, are now searching for what will define the US-China relationship for the next 50 years, because that relationship that was defined by the one-China policy and the three joint communiques has served everyone well," he said.

He said there is a very active mechanism between the two countries to put complex issues on the table. He was referring to the four cabinet-level dialogues agreed to by the two presidents at their Mar-a-Lago meeting in April in areas including the economy, diplomacy, security, social and cultural exchange, law enforcement and cybersecurity.

"This diplomatic and strategic dialogue is chaired by Secretary Mattis and myself," Tillerson said. "This dialogue is really to explore areas that we can work together on and explore areas where we have differences, and in this exploratory process create results that will over time hopefully allow us to define what this new relationship will be."

huanxinzhao@chinadailyusa.com