President Donald Trump's agreement Tuesday with North Korea's Kim Jong Un is a "tremendous" first step, according to CNBC's Jim Cramer.

"To say it's 'constructive' is to ignore the nuclear shadow the whole world has lived under because of this guy," said Cramer in response to comments by economist Mohamed El-Erian Tuesday morning on CNBC about the Singapore summit.

El-Erian, chief economic advisor at Allianz, and former CEO of bond giant Pimco, told "Squawk Box " that the market sees the Trump-Kim summit agreement as "a first, good constructive step. "

The accord, which is being called a comprehensive denuclearization agreement, said the United States and North Korea commit to hold follow-up negotiations and to cooperate to develop bilateral relations.

There was no mention of sanctions in the document, but Trump said after the summit that those penalties on Pyongyang would remain in place until "the menace of nuclear weapons" is removed.

"This is a man who was trying to build an ICBM that would hit Los Angeles," Cramer said on "Squawk on the Street. " "If you take that out then I'm sure there would be people who would say if Trump's other political issues weren't so polarizing that this is Nobel Prize material."

On Monday, Trump lashed out on Twitter at Canada and the European Union about trade. The president commented again on Tuesday, saying remarks by Canadian Prime Minister Justin Trudeau about him would cost Canada "a lot of money."

Stocks were little changed Tuesday, with the Dow Jones industrial average about 10 points lower intraday. Lack of detail in the agreement between the two countries, which included denuclearization of the Korean Peninsula, appeared to mute the gains.

Equities closed slightly higher Monday ahead of the meeting between Trump and Kim.

The "Mad Money " host on Monday noted the market's tepidness before the summit.

The White House did not immediately respond to a request for comment.

— CNBC's Everett Rosenfeld contributed to this report.