Although President Donald Trump warned Canada on September 1 that he would exclude them from a new trade deal if Canada did not comply with its demands, it is not clear that the Trump administration has the power to do so without congressional approval. :34-6 According to reports by the Congressional Research Service (CRS), one was published in 2017 and another on July 26, 2018, it is likely that President Trump would need congressional approval for fundamental changes to NAFTA before the changes are implemented. :34-6 Economists generally agreed that the U.S. economy as a whole benefited from NAFTA by increasing trade.   In a 2012 survey by the Global Markets Initiative`s panel of economic experts, 95% of participants said that U.S. citizens benefited on average from NAFTA, while no one said that NAFTA was detrimental to U.S. citizens on average.  A review of the 2001 Journal of Economic Perspectives showed that NAFTA was a net benefit to the United States.  A 2015 study showed that welfare in the United States increased by 0.08% and intra-block trade in the United States by 41% due to NAFTA tariff reductions.  The impetus for a North American free trade area began with U.S.
President Ronald Reagan, who made the idea part of his campaign by announcing his candidacy for president in November 1979.  Canada and the United States signed the Canada-U.S. Free Trade Agreement in 1988, and shortly thereafter, Mexican President Carlos Salinas de Gortari decided to address U.S. President George H.W. Bush to propose a similar agreement to make foreign investment after the Latin American debt crisis.  When the two leaders began negotiations, the Canadian government of Prime Minister Brian Mulroney feared that the benefits that Canada had gained through the Canada-U.S. free trade agreement would be undermined by a bilateral agreement between the United States and Mexico, and asked to be associated with the U.S.-Mexico talks.  In 2009, the United States had a trade surplus with NAFTA countries of $28.3 billion for services and, in 2010, a trade deficit of $94.6 billion (36.4% per year) for goods. This trade deficit represented 26.8% of the total U.S. trade deficit.  A 2018 study on international trade published by the Center for International Relations identified irregularities in NAFTA trade patterns using network theory analysis techniques.
The study showed that the U.S. trade balance was influenced by the potential for tax evasion in Ireland.  Supporters of NAFTA in the United States stressed that the pact was a free trade agreement and not an agreement on the Economic Community.  The free movement of goods, services and capital did not extend to work. By proposing what no comparable agreement had attempted to open up to a „great third world country“ – NAFTA avoided the establishment of a common social policy and employment. The regulation of the labour market and employment has remained exclusively due to national governments.  The U.S. Chamber of Commerce attributed to nafta that U.S. trade in goods and services with Canada and Mexico increased from $337 billion in 1993 to $1.2 trillion in 2011, while the AFL-CIO signed the agreement for sending 700,000 U.S. production jobs to Mexico during that period.
 If the original Trans-Pacific Partnership (TPP) were to enter into force, existing agreements, such as NAFTA, would be reduced to provisions that do not conflict with the TPP or require greater trade liberalization than the TPP.  However, only Canada and Mexico would have the prospect of becoming members of the TPP after U.S. President Donald Trump withdrew the United States from the agreement in January 2017. In May 2017, the remaining 11 members of the TPP, including Canada and Mexico, agreed to pursue a revised version of the trade agreement without the United States.