According to South Korea's National Security Chief, Chung Eui-yong, speaking to the press after a meeting about North Korea with President Trump on March 08, 2018:
"I explained to President Trump that his leadership and his maximum
pressure policy, together with international solidarity, brought us to
this juncture. I expressed President Moon Jae-in’s personal gratitude
for President Trump’s leadership."
Full transcript:
South Korea official's speech on Trump-North Korea leader meeting by May
According to South Korea's Foreign Minister, Kang Kyung-wha, speaking to CNN on April 26, 2018:
South Korea's foreign minister has said she believes President Donald
Trump is largely responsible for bringing North Korean leader Kim
Jong-un to the negotiating table.
Speaking ahead of Friday's historic summit between the leaders of
North and South Korea, Kang Kyung-wha told CNN that the US President
had played a significant role in bringing the two sides together.
"Clearly, credit goes to President Trump," Kang told CNN's Christiane
Amanpour in Seoul. "He's been determined to come to grips with this
from day one."
CNN report: South Korea credits Trump for opening door to talks with North
According to the President of South Korea, Moon Jae-in, as reported by the BBC on April 27, 2018:
South Korean President Moon Jae-in said publicly too that President
Trump deserved big credit for bringing about talks to discuss peace
with the North. "It could be a resulting work of the US-led sanctions
and pressure."
BBC report: Does Trump deserve the credit for peace talks with North Korea?
President Moon went further, saying that President Trump should receive the Nobel Peace Prize:
Donald Trump should win the Nobel Peace Prize for his efforts to unify
Korea, the South Korean President has reportedly suggested.
"President Trump should win the Nobel Peace Prize. What we need is
only peace," Mr Moon told a meeting of senior secretaries, according
to an official who briefed media.
In floating the idea of a Trump Nobel, Mr Moon was responding to a
comment by Lee Hee-ho, the widow of late South Korean President Kim
Dae-jung.
She said Mr Moon deserved to win the prize in recognition of his peace
efforts, leading him to say Mr Trump should get it.
Sky News report: Donald Trump deserves the Nobel Peace Prize, says South Korea's President
New York Times report: A Trump Nobel Peace Prize? South Korea’s Leader Likes the Idea
According to German Chancellor Angela Merkel, in a joint press conference with President Trump on April 27, 2018:
"Today, we meet at a point in time where it has become very clear that
the strength of the American president, where he really saw to it that
the sanctions against North Korea are respected, has opened new
possibilities, opened new ways."
CNBC report: Trump and German Chancellor Angela Merkel hold joint press conference