US President Donald Trump has urged North Korea to "come to the table" and discuss giving up its nuclear weapons.
Striking a different tone from previous fiery rhetoric, he said he "hoped to God" he did not have to use the US military against Pyongyang.
Mr Trump was speaking at a press conference with his South Korean counterpart Moon Jae-in in Seoul, as part of his tour of Asia.
The US leader has previously threatened "fire and fury" against Pyongyang.
He is on a five-nation tour of Asia, where North Korea's nuclear ambitions have been high on his agenda.
At a press conference, Mr Trump and Mr Moon reiterated their call for the North to denuclearise, with Mr Trump saying it "makes sense for North Korea to come to the table", and to "do the right thing, not only for North Korea but for humanity all over the world".
Though the US had deployed a significant military presence in the region, he said he "hoped to God" he would not have to use it against North Korea.
The two leaders also called on China and Russia to put pressure on Pyongyang, and said they were lifting the limit on South Korean missile payloads, which they had agreed to do in September.
Mr Trump also said that South Korea would be ordering "billions of dollars" in military equipment from the US, which he said would reduce their trade deficit.
It was unclear if a deal was already struck, but Mr Moon said they had agreed to "begin consultations on acquisitions" that would enhance South Korea's defence capabilities.
Mr Trump had earlier tweeted that "massive military and energy orders" from Japan were also happening, and claimed on Monday that Japan could shoot down Pyongyang's missiles with US equipment.
Japan's leader Shinzo Abe said earlier that he was considering it.
Though the US president will only spend about 24 hours in South Korea, it is perhaps the most symbolic stop in his Asian tour, says the BBC's Robin Brant in Seoul.
The trip is designed to bolster the military alliance that has long protected South Korea, and strength in unity is the message they want to send to North Korean leader Kim Jong-un just across the border, says our correspondent.
But the two leaders also have their differences. Mr Trump has previously accused Mr Moon's government of trying to appease the North.
He has also previously criticised the free trade agreement between the US and South Korea, and has made clear he wants to re-negotiate its terms.
Mr Trump, during the press conference, said the deal had been "quite unsuccessful" for the US, and that the two countries were going to "pursue a much better deal".
Protests against Mr Trump, as well as counter-rallies welcoming him, have been held in Seoul and elsewhere.
Many in South Korea are hoping that Mr Trump will not repeat his strong rhetoric against North Korea, which many here regard as unnecessary and incendiary, says our correspondent.
Mr Trump will be going to China, Vietnam and the Philippines in the coming week.