"So we won't let ourselves be ripped off again and again".
Meanwhile, when asked about Kudlow and Navarro's comments, Canadian Foreign Minister Chrystia Freeland said that she was thankful she was "not responsible for explaining the reasoning behind any comments made by the officials of any foreign government".
In a statement to MPs on the summit, Mrs May praised Mr Trudeau's "skilful" handling of proceedings and said the leaders had established "common ground" on a range of matters.
In recent weeks, trading partners of the United States have criticised new tariffs on steel and aluminium imports imposed by the Trump administration.
"I don't want us to keep inflating our language", she added, saying the word "depressed" was "already a lot, coming from me", in an ironic reference to her usual unflappable appearance.
Merkel did not know Trump planned to do this and only found out he pulled out from the "arduously negotiated" declaration while she was returning from the summit.
Vladimir Putin Dismisses G7 Criticism As "Babbling", Calls For Cooperation
Vienna has been discussed as a possible venue for a summit between Vladimir Putin and Donald Trump , the Kremlin said Saturday. President Barack Obama's landmark 2015 nuclear accord with Iran over the objections of European allies and other nations.
On Saturday morning Trump said he was open to getting rid of the tariffs if the other countries agreed to a more pure form of free trade.
Amid the ongoing trade dispute with the US, Merkel called on European countries to remain united and to continue their efforts to prevent an escalation.
May thanked Canadian Prime Minister Justin Trudeau for organizing the summit.
U.S. President Barack Obama, right, and German Chancellor Angela Merkel are seated together at a G7 working dinner in Brussels, Belgium, Wednesday, June 4, 2014.
Other G7 countries lobbied unsuccessfully at the summit for the U.S. oto reverse its tariffs on imported steel and aluminium imports.
"We have spent two days to secure a text and commitments. This is probably not because he does not understand, but because of domestic reasons", said the official, who spoke on condition of anonymity.