Oil prices rose 2% on Monday after a trade deal between the U.S. and the European Union, and U.S. President Donald Trump's announcement that he would shorten the deadline for Russia to end its war in Ukraine or face sanctions.

Tariffs are taxes charged on goods bought from other countries. Typically, they are a percentage of a product's value. So, a 15% tariff means that a $100 product imported to the US from the EU will have a $15 dollar tax added on top - taking the total cost to the importer to $115.

Following his meeting with the head of the European Commission, Trump declared that EU exports to the US would be subject to a baseline 15% tariff. EU leaders stand divided on the deal.