Eurosceptic Mr Kawczynski, who said Mr Trump had managed to boost the US economy significantly, added it was now “absolutely crucial” to appoint the right replacement to liaise with Washington as Britain eyes a bumper trade deal with the US after Brexit.
Mr Darroch stepped down after confidential cables in which he branded the Trump administration “inept” and “dysfunctional” were leaked to the media.
The resultant publicity enraged Mr Trump, who aired his views in a series of angry tweets in which he branded Mr Darroch “wacky” and “a very stupid guy”, and said the US would no longer deal with him.
Mr Darroch subsequently tabled his resignation, saying his job had been made impossible by the leaking of the information.
Prior to him quitting, during a televised debate with rival Jeremy Hunt, Boris Johnson, who Mr Kawczynski is backing for leadership of the Conservative Party, refused to say whether he would keep Mr Darroch in his post should be become Prime Minister.
Critics later suggested Mr Johnson’s lack of support had played a part in his decision, with Foreign Office minister Alan Duncan claiming the former Foreign Secretary of “throwing him under the bus”.
However, Mr Kawczynski, who met Mr Johnson for discussions on a number of policy areas last month, told Express.co.uk since Mr Trump had become President, the US economy was booming, with the US now a net exporter.
The Tory MP for Shrewsbury and Atcham added: “If that’s dysfunctional government, give me dysfunctional government any day.
“If I was him, if I had any doubts about the US Government I would be discussing them at the Foreign and Commonwealth Office, not
putting them in cables.
“The entire episode must serve as a warning – be careful what you put in these cables, which as I understand it were sent to about 100 people.
“I feel sorry for the chap but that’s the way it is.”
As for Mr Darroch’s replacement, Mr Kawczynski said: “We need to have somebody in that position who is massively experienced as we
prepared to negotiate a crucial free trade deal with the United States.”
Mr Kawczynski also stressed his belief that Mr Johnson was best placed to lead the UK into a successful new phase.
He said: “What Boris has done is underline the reasons to be positive about this.
“There’s been far too much negativity in the years since the referendum, and that extends to Theresa May, whose Brexit policy was basically one of damage limitation.
“We’ve had this drip-drip of negativity which has been most unhelpful rather than stressing the benefits of leaving the European Union.”
Mr Kawczynski’s words echoed those of Mr Johnson speaking at a rally in Bedfordshire on Saturday.
The former London Mayor said there was “ample scope” to get a good trade deal from the European Union, but said it depended on the EU and whether they want to have a good trade relationship with the UK.
In order to get that Britin needed to be ready to leave without a deal, he insisted.