Image copyright Reuters Image caption Andrew Kim had a spot at the table in May for Pompeo's talks with Kim

A US team of negotiators has been talking to counterparts in North Korea ahead of the showdown talks between the two leaders in Singapore.

Secretary of State Mike Pompeo has played a leading role in a number of working sessions that concluded on Monday.

Their aim was to hammer out the vital questions and areas to discuss later.

The Washington Post reports that the two leaders will meet one-on-one before the teams of experts join them.

As well as Mr Pompeo, Chief of Staff John Kelly and National Security Adviser John Bolton are expected to be there - he has already infuriated the North Koreans with his tough line.

So who else will there be on the US side?

Andrew Kim

Korean-American Andrew Kim is the head of the CIA's Korea Mission Centre.

Mr Kim was born and raised in South Korea under the name Kim Sung-hyun, the Washington Post reported.

He attended the prestigious Seoul High School, which boasts South Korea's national security adviser and intelligence agency head as alumni, before moving to the US during college.

Image copyright AFP Image caption Andrew Kim (circled) arrives in North Korea with Mike Pompeo in May

He worked with the CIA for the majority of his career, serving in Moscow, Beijing, Bangkok and Seoul.

Mr Kim had retired, but the CIA brought him back to lead the new Korea Mission Centre last May.

In the lead up to the summit, he seems to have become Mr Pompeo's right-hand-man for all things North Korea related - including planning strikes, a South Korean presidential adviser said.

He has been described by South Korean and Japanese media as a "messenger from hell" due to his hawkish stance on North Korea.

Sung Kim

Veteran diplomat Sung Kim is the current US ambassador to the Philippines.

He served as the ambassador to South Korea between 2011-2014 and was a US special envoy in the Six-Party talks.

Image copyright Getty Images Image caption Ambassador Kim at a ceremony in the Philippines

Mr Kim was born in Seoul but grew up in Los Angeles. As a diplomat, he served in Tokyo, Kuala Lumpur and Hong Kong.

During his time in Washington, he was the special representative for North Korea policy in Washington, director of the Office of Korean Affairs and Staff Assistant in the Bureau of East Asia and Pacific Affairs.

He recently led the US delegation to meet North Korean officials at the border to discuss talks, Reuters reported.

A South Korean official told Reuters Mr Kim was "capable, level-headed, cautious", with a "solid grasp of the issues and [he] knows North Koreans well".

Randall Schriver

A top aide to Secretary of Defense Jim Mattis, he has been instrumental in laying the groundwork for the upcoming summits, according to the White House.

The former Navy intelligence officer and State Department diplomat now serves as Assistant Secretary of Defense for Asian and Pacific Security Affairs, and has been holding talks with North Korean delegates at the DMZ for weeks.

Image copyright US Department of Defense Image caption Randall Schriver is a top aide to Secretary of Defense Jim Mattis

In June he travelled to Pyongyang with Mr Pompeo.

From 1994-98 he worked for the Pentagon on day-to-day relations with the Chinese military and bilateral relations with Taiwan.

He previously served as president and CEO of Project 2049, a think tank specialising in Asian security issues.

The native of the US state of Oregon has run in four triathlons, according to Armitage International consulting firm, which he co-founded.

Allison Hooker

She is a Korean peninsula specialist on the White House National Security Council, which she joined in 2014 under former President Barack Obama.

She was formerly a member of the Department of State Bureau of Intelligence and Research where she was tasked with North Korean nuclear policy.

Image copyright Getty Images Image caption Allison Hooker, right, with Vice-President Biden at a nuclear security summit in 2016

In 2017, she was chosen by the White House to be part of the US delegation to the closing ceremony of the Olympic games in PyeongChang. However, she reportedly did not meet with any North Korean officials during her time there.

In 2014, under President Obama, she travelled to North Korea with then-director of National Intelligence James Clapper to negotiate the release of two American detainees. During the brief trip, she also met powerful Korean General Kim Yong-chol.

A wildcard - Ivanka Trump

Image copyright Getty Images Image caption Ivanka was at the heart of the Winter Games diplomacy

The wild card on the US delegation is the US president's own daughter, and White House adviser, who led the US delegation to the 2018 Winter Olympics. The games, which were attended by North Korea, paved the way for these peace talks.

During her time there, she sat in the stands beside the North Korean leader's sister, Kim Yo Jong. At one point the two women shook hands as cameras documented the moment.

The absence of US First Lady Melania Trump from Singapore has only added to the speculation that Ms Trump may make a surprise appearance.