But in an interview with The Washington Post after he left South Korea, Mr. Pence suggested that the United States was open to a meeting, even indicating that it would enter talks without preconditions.
“So the maximum pressure campaign is going to continue and intensify,” Mr. Pence said of the punishing sanctions imposed on the North by the United Nations. “But if you want to talk, we’ll talk.”
Agreeing to talks before the North Koreans have demonstrated a willingness to dismantle their weapons program would be a subtle but potentially significant shift in Washington’s approach, and a win for Mr. Moon, who has hoped to bring North Korea and the United States to the negotiating table.
When Mr. Pence and Mr. Moon met last week, the allies apparently found common ground: They would agree to talks without set rules, but they will continue to use sanctions as leverage.
“President Moon and I reflected last night on the need to do something fundamentally different,” Mr. Pence told reporters on Friday after meeting with the South Korean leader.
The allies, he said, would demand “at the outset of any new dialogue or negotiations” that North Korea “put denuclearization on the table and take concrete steps with the world community to dismantle, permanently and irreversibly, their nuclear and ballistic missile programs.”
“Then, and only then, will the world community consider negotiating and making changes in the sanctions regime that’s placed on them today,” Mr. Pence said.
During Mr. Pence’s trip to South Korea, Kim Yo-jong, the sister and special envoy of the North Korean leader Kim Jong-un, also visited the South as part of an Olympic delegation. She extended an invitation from her brother to Mr. Moon for a summit meeting in North Korea.
Mr. Moon, who invited athletes from the North to participate in the Olympics — where they marched with South Korean athletes under a united Korean flag during the opening ceremony — has seen the Games as an important step toward promoting peace on the Korean Peninsula.
If Mr. Pence’s comments reflect official White House policy, it could mean that the Trump administration has been heartened by a lull in North Korea’s nuclear and missile tests in recent weeks and an emerging détente between the two Koreas.
North Korea has not conducted any major weapons tests since Nov. 29, when it launched an intercontinental ballistic missile powerful enough to reach the mainland United States.
Even if talks start between North Korea and United States, the gap between the countries remains wide.
North Korea has said that it would not bargain away its weapons, and would only discuss mutual arms reduction.
Some analysts said North Korea would never give up its nuclear weapons, and that it would use any future talks with Washington to be accepted as a nuclear power and win large economic concessions, in return for agreeing not to advance its nuclear weapons program any further.
Others analysts believe the North is willing to talk because it desperately wants to find a way to ease the sanctions that have taken a toll on its economy.