The crossing over the Kerch Strait, now the longest sea bridge in Europe, has been the subject of political tension since the 2014 annexation of the Crimean peninsula and city of Sevastopol by Russian Federation.
Russian President Vladimir Putin yesterday opened a bridge to occupied Crimea behind the wheel of a KAMAZ.
The Crimean Bridge became the longest bridge in Russian Federation - it is 19 kilometers long. Russian Federation built the bridge in defiance of Ukraine, which said the move showed cynical disregard for global law.
In a post on Facebook, the Russian embassy in the United States said: "As one could predict, Washington is not happy with that".
US Department of State Spokesperson Heather Nauert told reporters on Tuesday that the construction allegedly impedes navigation and "limits the ability to bring in goods via ship".
"France condemns the construction by Russian Federation of the Kerch Bridge, which deprives Ukraine of full access and the use of its internationally recognized territorial waters", a French Foreign Ministry spokeswoman said.
Companies belonging to Arkady Rotenberg, Mr Putin's childhood judo sparring partner, were tasked with completing the national prestige project. Some Russians are calling it "Putin's bridge", created to link Crimea into Russia's transport network.
The bridge should ease bottlenecks for travelers and goods traveling to and from Russian Federation proper, AFP says.
Ukrainian President Petro Poroshenko called the illegal construction of the Kerch Bridge another indication of the neglect of worldwide law by the Kremlin.
The bridge, an ambitious project criticized by the State Department and described as "another violation of Ukraine's sovereignty and territorial integrity by Russia" by the European Union, is the newest lucrative operation for Putin's closest allies.
"Today, both in a practical sense and from a symbolic point of view, is an extremely important day", he added.
The bridge is split into two sections, one for vehicles, which Putin inaugurated on Tuesday and another for trains, which is set to be unveiled next year.
The railway bridge is not yet finished and has a deadline of the end of 2019.