U.S. President Donald Trump's tariff decisions since he took office on January 20, from imposing sweeping duties to abruptly pausing some of them, have shocked financial markets and sent a wave of uncertainty through the global economy.

Here is a timeline of the major developments:

February 1 - Trump imposes 25% tariffs on Mexican and most Canadian imports and 10% on goods from China, demanding they curb the flow of fentanyl and illegal immigrants into the United States. 

February 3 - Trump suspends his threat of tariffs on Mexico and Canada, agreeing to a 30-day pause in return for concessions on border and crime enforcement. The U.S. does not reach such a deal with China.

February 7 - Trump delays tariffs on de minimis, or low-cost, packages from China until the Commerce Department can confirm that procedures and systems are in place to process them and collect tariff revenue.

February 10 - Trump raises tariffs on steel and aluminium to a flat 25% "without exceptions or exemptions". 

March 3 - Trump says 25% tariffs on goods from Mexico and Canada will take effect from March 4 and doubles fentanyl-related tariffs on all Chinese imports to 20%.

March 5 - The president agrees to delay tariffs for one month on some vehicles built in Canada and Mexico after a call with the CEOs of General Motors and Ford and the chair of Stellantis.

March 6 - Trump exempts goods from Canada and Mexico under a North American trade pact for a month from the 25% tariffs.

March 26 - Trump unveils a 25% tariff on imported cars and light trucks.

April 2 - Trump announces global tariffs with a baseline of 10% across all imports and significantly higher duties on some of the U.S.' biggest trading partners.

April 9 - Trump pauses for 90 days most of his country-specific tariffs that kicked in less than 24 hours earlier following an upheaval in financial markets that erased trillions of dollars from bourses around the world. 

The 10% blanket duty on almost all U.S. imports stays in place. 

Trump says he will raise the tariff on Chinese imports to 125% from the 104% level that took effect a day earlier. This pushes the extra duties on Chinese goods to 145%, including the fentanyl-related tariffs imposed earlier.

April 13 - The U.S. administration grants exclusions from steep tariffs on smartphones, computers and some other electronics imported largely from China.

April 22 - The Trump administration launches national security probes under Section 232 of the Trade Act of 196...