A research institute in Sweden says weapons imports by countries in Europe in the period between 2019 and 2023 nearly doubled compared to the previous five years. The period includes Russia's ongoing invasion of Ukraine, which began in 2022.

Stockholm International Peace Research Institute, or SIPRI, released on Monday a report on global transfers of weapons between 2019 and 2023.

SIPRI calculates the volume of international transfers of major conventional weapons using a unique indicator based on the known unit production costs of a core set of weapons, rather than the financial value of the transfers.

The report said arms imports by European countries were 94 percent higher in 2019-2023 than in 2014-2018.

It said Ukraine was the largest arms importer in Europe, as its imports grew more than 60-fold, accounting for 23 percent of the region's arms imports in 2019-2023. At least 30 countries supplied major weapons to Ukraine after Russia began its full-scale invasion in February 2022.

The institute said much greater demand for air defense systems has been seen in Europe, triggered by Russia's missile campaign against Ukraine.

The report also said Japan increased arms imports by 155 percent in the 2019-2023 period compared to the 2014-2018 period, attributing the growth mainly to tensions with China and North Korea. It said that Japan is "investing heavily in long-range strike capabilities."