US president Donald Trump today called off his threat to impose tariffs on imports from Mexico after pronouncing himself satisfied with the immigration proposals submitted by the Mexican government.

"The Tariffs scheduled to be implemented by the US on Monday, against Mexico, are hereby indefinitely suspended," Trump announced through Twitter shortly after returning to Washington from a weeklong tour of Europe.

Mexican officials pledged to use the country's National Guard to stem the flow of immigrants from other Latin American countries, a promise that will be finalized in coming weeks.

Trump on 31 May, just before leaving the US, threatened to impose a 5pc tariff on "all goods" from Mexico starting on 10 June, and to ratchet the duties up to 25pc by October unless the country reduced the number of migrants crossing into the US illegally.

A high-level Mexican government delegation headed by foreign minister Marcelo Ebrard, visiting Washington on 4-7 June, submitted proposals on immigration enforcement. US vice-president Mike Pence and other officials said yesterday and earlier today the proposals were not sufficient to address Trump's concerns, but left the decision on tariffs to him.

"Mexico, in turn, has agreed to take strong measures to stem the tide of Migration through Mexico, and to our Southern Border," Trump said in another tweet, noting that the State Department will release details of what Trump dubbed a "signed agreement."

The agreement, which is actually a joint declaration by the US State Department and Mexico's Foreign Ministry, lists broad measures the two countries plan to implement to address immigration. Mexico has pledged to deploy its National Guard throughout its territory to prevent migrants from Central America from traveling to the US border.

The countries will review progress on implementation every 90 days and "in the event the measures adopted do not have the expected results, they will take further actions," according to the declaration. "The US and Mexico will continue their discussions on the terms of additional understandings to address irregular migrant flows and asylum issues, to be completed and announced within 90 days, if necessary," the declaration said.

Mexico's president Andres Manuel Lopez Obrador said that "thanks to the support of all Mexicans, the imposition of tariffs on Mexican products exported to the US was avoided."

The prospect of tariffs on imports from Mexico, including heavy crude, has chilled the US energy industry that operates in an interconnected North American market.

US sanctions on Venezuela and Canadian production cuts already have stressed the heavy crude market and a tariff on imports from Mexico would exacerbate the situation, industry group American Fuel and Petrochemical Manufacturers vice president for government relations Geoff Moody told Argus earlier today. "Our refineries are not going to be running as efficiently as they can be, and therefore are going to be less competitive in this global refined product marketplace," Moody said before the agreement was announced.

Individual refiners said that a 5pc tariff would not severely impact trade between the countries, but were concerned about a potential escalation.

AFPM, the American Petroleum Institute and other business groups have strongly urged the administration to desist from the imposition of tariffs.

The administration dismissed negative implications for US industry and consumers of starting a trade war with the US' largest trade partner as irrelevant. "The president has no higher priority than ending the immigration that is flooding our southern border," Pence said yesterday.

But in the end the decision was Trump's alone.

Even with the Mexico tariffs averted for now, the administration's trade wars with China and disputes with other major trading partners are stressing the industry. The trade actions have created long-term uncertainty for US oil and natural gas producers dependent on access to foreign markets, an energy industry insider said.

Trump in March threatened to shut down the US-Mexico border to commercial traffic over immigration concerns, only to back off the threat.

"He makes these threats, and then he backs off when he sees the danger," Senate Democratic leader Chuck Schumer (New York) said on 4 June. "I have a feeling that this one just popped into his head."