The US and its NATO partners are conducting military drills in a region of Romania that borders Ukraine. Thousands of soldiers will gather to simulate repelling an invasion on the Black Sea coastline.

Dubbed “Sea Shield 23,” the war games kicked off on March 20 and will run until April 2. The US and 11 other NATO countries are participating in the Romanian-led military exercises. Nearly 3,500 soldiers, 30 naval ships, 14 aircraft and 15 other “fast intervention” boats are participating in the live-fire operations, which will occur in the Black Sea and Romania’s Danube Delta. Troops taking part in the Sea Shield drills will come within 20 miles of the Ukrainian border.

“The multinational exercise ‘Sea Shield 2023’ is the most complex training event, planned and conducted by the Romanian Naval Forces, through the Naval Component Command, in the 2023 training year,” the Romanian Navy said in a press release.

Since the Russian invasion of Ukraine, the US has conducted several rounds of war games in Eastern Europe to simulate a similar conflict and develop strategies for Kiev. Investigative journalist Seymour Hersh reported that last summer, the Joe Biden administration used the cover of war games in the Baltic Sea to plant explosives on the Nord Stream pipelines. In September, those explosives were detonated destroying the natural gas pipelines linking Russia and Germany.

Over the past year, the North Atlantic alliance has increased its force posture in what it regards as its “eastern flank,” which is made up of eight countries that stretch from the Baltics to the Black Sea, including Romania. NATO is concurrently conducting the “Crystal Arrow 23” war games in Latvia, which will see Danish soldiers train Riga’s Mechanized Infantry Brigade.