But observers say Trump's string of bellicose threats directed at North Korean leader Kim Jong Un and his country in 2017 - including his vow to rain "fire and fury" on North Korea and to "totally destroy" the nation of 25 million people if it threatened the USA or its allies - contributed much to the fears of a bloody and possibly nuclear conflict at the time.
He "gave me the most lovely copy of a letter that he sent to the people who give out a thing called the Nobel Prize", Trump said during his announcement that he was declaring a national emergency at the southern border. He said Mr Abe sent the nomination because Japan now feels "good" and "safe" after North Korean ballistic missile launches ceased.
During a White House news conference on Friday, Trump said the Japanese premier had given him "the most lovely copy" of a five-page nomination letter to the Norwegian Nobel Committee.
A spokesman for the Japanese Embassy in the USA was not able to comment to The Daily Caller News Foundation about Trump's claims.
In early 2018, two Norwegian lawmakers nominated President Trump for the 2019 Nobel Peace Prize for his work in reaching an agreement on North Korea's denuclearisation.
Trump said early exchanges with Kim were filled with "fire and fury", but since their first meeting past year in Singapore, the two have established a good relationship.
Abe has sought to build rapport with Trump, partly as Japan is struggling to make substantial progress in efforts to resolve the issue of North Korea's past abductions of Japanese nationals.
Trump complained Friday that Obama was there "for about 15 seconds" before he was awarded the prize.
In response, Mr Abe said: "In light of the Nobel committee's policy of not disclosing recommenders and nominees for 50 years, I decline to comment". He didn't even know what he got it for.
His message was backed by former CIA Director John Brennan, who told NBC News that Obama was never on the brink of starting any war with North Korea, "large or small".
"I think President Trump has mistaken PM Abe with someone else". "He's not making Abe look very good".
In recent months, Trump has showered praise on Kim, whom he used to derisively call "Little Rocket Man".
Trump's landmark June 2018 summit with Kim in Singapore was replete with pomp but thin on substance.