US President Donald Trump says that years of “strategic patience” with North Korea have failed and it is now time for a “determined response”.
“Together we are facing the threat of the reckless and brutal regime,” Mr Trump said at a press conference with South Korean President Moon Jae-in.
Mr Trump called on North Korea to “choose a better path… quickly”.
Separately, Mr Moon said that it was necessary to continue to engage in dialogue with North Korean leaders.
The South Korean president added that his country would pursue defence reforms and continue to build up the capacity to defend itself.
Mr Moon said the North Korea issue was a top priority during the talks, stressing that “only strong security can bring about genuine peace” in the Asia-Pacific region.
Speaking at the White House, Mr Trump said that the “era of strategic patience with the North Korean regime has failed, many years it has failed,” adding: “Frankly, that patience is over.”
The US leader said that Washington was “working closely with South Korea and Japan, as well as partners around the world, on a range of diplomatic, security and economic measures to protect our allies and our own citizens from this menace known as North Korea”.
It comes after the US announced sanctions on a Chinese bank accused of laundering North Korean money, sparking an angry response from China.
A foreign ministry spokesman urged the US to “stop wrongful actions” to avoid harming co-operation between the two nations.
The US said the blacklisting, which included sanctions on a Chinese shipping company and two Chinese nationals, was aimed at cutting funds to North Korea’s weapons programmes.
“We will follow the money and cut off the money,” Treasury Secretary Steven Mnuchin told a news conference.
But he said the move was not a response to Chinese inaction on North Korea, adding: “This is not directed at China, this is directed at a bank, as well as individuals and entities in China.”
Washington has been pushing Beijing for tougher measures amid a series of missile tests by Pyongyang. But in a tweet earlier this month, Mr Trump said China’s actions had “not worked out”.