The planned meeting between US President Donald Trump and North Korean leader Kim Jong-un has raised expectations for a breakthrough in the decades-long standoff over Pyongyang's nuclear weapons and ballistic missile programs.
While an advance team works in Singapore, diplomats discussed the summit agenda at meetings in the Demilitarized Zone between North and South Korea, said White House spokeswoman Sarah Sanders.
"We feel like things are continuing to move forward and good progress has been made", Sanders said.
Trump has been advised not to offer Kim any concessions, as the White House seeks to put the onus on the North Koreans to make the summit a success, one USA official said.
Mr Putin told Austrian public broadcaster ORF on Monday that the denuclearisation of the North shouldn't be "one-way road" and he hoped the USA would reward Pyongyang if it suspended nuclear and missile tests.
The designated areas include the central region of Singapore, where its foreign ministry, the USA embassy and several hotels are located and the southern region where summit is scheduled to take place.
Photo provided by the Korean Central News Agency (KCNA) on May 10, 2018 shows Kim Jong Un, top leader of the Democratic People's Republic of Korea (DPRK), talking with visiting U.S. Secretary of State Mike Pompeo (not in the picture) on May 9, 2018.
Trump's recent statement that he doesn't want to keep using the phrase "maximum pressure" against North Korea reinforced those fears.
Rodman, who played with the Pistons from 1986-1993, is no stranger to North Korea.
In keeping with normal practice, Singapore, as the host nation, will have to pay out for general security and various other expenses.
He stressed that the Singapore meeting is part of a "process" that will go on for some time: "I told them today, 'Take your time".
The softening of Trump's rhetoric was more palpable after he received North Korean leader Kim Jong-un's special envoy at the White House last week.
Trump said last week he expected an eventual "very positive result" with North Korea but dampened expectations for a breakthrough in Singapore, saying it could take several meetings to reach an agreement. We can go fast, we can go slowly.
Kim is unlikely to spend much time in Singapore.
Rodman's spokesman, Darren Prince, says a trip to Singapore is not set in stone.
There has also been speculation Kim does not wish to leave North Korea for an extended period of time as this may encourage any remaining opponents to his rule to seize the opportunity to stage a coup.