At a news conference with Japanese Prime Minister Shinzo Abe in Tokyo, US President Donald Trump called North Korea a "menace" and said that Japan and said US had to work together to counter the "dangerous aggressions" of the North.

The North's nuclear program was "a threat to the civilized world and international peace and stability," he told reporters. He added that "some say my rhetoric is strong, but look what's happened with weak rhetoric over the last 25 years."

Read more: Trump's Japan trip a 'symbolic show of solidarity' 

He reiterated his bullish stance that the "era of strategic patience" was over and that "all options are on the table."

A similarly hawkish Abe welcomed the US's policy, saying that the two countries agreed "100 percent" on North Korea and that it was now crucial to exert maximum pressure on the repressive regime.

Trump: Japan 'winning' in trade relationship

Earlier on Monday, President Trump told American and Japanese business leaders that Japan had been "winning" the trade relationship with the US "for the last many decades."

"The US has suffered massive trade deficits with Japan," he said, adding that current trade arrangements were "not fair and not open."

Trump praised Japan for buying US military hardware but lamented that while "many millions of cars are sold by Japan into the United States ... virtually no cars go from the United States into Japan."

Trump also said he expects Japan to purchase "massive amounts" of military equipment from the United States. Japan will be able to shoot missiles from North Korea "out of the sky" with that equipment.

Abe replied that Japan would only shoot down missiles if absolutely necessary.

New economic ties - without TPP

The US leader said he wanted to reshape the two nations' economic ties, and despite abandoning the Trans-Pacific Partnership (TPP) — which the US had negotiated with several Asian and North and South American countries — Trump said he wanted "more trade than anyone ever thought under TPP."

"We'll have to negotiate that out and it'll be a very friendly negotiation," one that would be done "quickly and easily," Trump said on the second day of his trip to Japan, one of America's biggest trade partners.

Trump's remarks tally with his election promises to US voters to negotiate better trade terms for the US and to bring back millions of jobs that have moved overseas over the past two decades. His strategy has been criticized as being protectionist.

Trump is in Tokyo as part of a 12-day Asian tour that will be dominated by trade talks and the North Korean standoff.

Read more: North Korean defector pushes for diplomacy in US testimony

'Open' to talks on North Korea

In an interview with the US TV show "Full Measure," Trump said he would "certainly be open" to meeting North Korean leader Kim Jong Un.

"I would sit down with anybody. I don't think it's a strength or weakness, I think sitting down with people is not a bad thing," he said in remarks made before he left for Asia. But he added that talks may still be some way off.

The president has previously vowed to "totally destroy" North Korea if it threatened the US, after Pyongyang stepped up its nuclear and ballistic missile tests.

Trump's five-nation tour of Asia will also take in South Korea, China, Vietnam and the Philippines.

He's expected to pressure Chinese leaders to do more to rein in Pyongyang's nuclear ambitions. The North Korea issue is also expected to dominate talks with Russian President Vladimir Putin, who will also fly to Asia this week for summits in Vietnam and the Philippines.

ng/kms (AP, AFP, Reuters)