In 2014, as the Ukrainian government lost Crimea and a portion of the Donbas to Russia and Russian-backed separatists, respectively, it unveiled a plan called "Project Wall" through which it sought to erect a fortified border barrier along the rest of the international border, with the goal of blocking any further Russian incursions into the country.

[7] Since 30 November 2018, Ukraine has banned all Russian males aged 16–60 from entering the country, albeit with room for exceptions on humanitarian grounds.

[12][better source needed] Prior to this law, Ukraine allowed the "internal passport" to be used for travel to Russia.

[13] After the fall of the Russian Empire, several factions sought to create an independent Ukrainian state, alternately cooperating and struggling against each other.

Peace talks started on 23 May 1918 in Kyiv, where the Russian delegation was headed by Christian Rakovsky and Dmitry Manuilsky, while the Ukrainian - by Serhiy Shelukhin [uk] (Ambassador of Ukraine to Russia).

[13] Yet any further negotiations led nowhere and were terminated by the Ukrainian delegation in October 1918 as it was becoming apparent that the Russian was using their time more for the pro-Soviet propaganda.

[13] To Ukraine also was ceded some territory of the right bank of the Kalmius river just east of Mariupol "to ensure the proper administration of the city and port".

[13] On September 18, 1918, between Don and Ukraine the Don-Ukrainian Commission was created for the administration of the Taganrog Industrial District, based in Kharkiv.

The Ukrainian government claimed mainly some parts of the Kursk and Voronezh gubernia, which were home to a Ukrainian-speaking population.

As a result of the border dispute of the 1920s, Ukraine was granted approximately one-third of the claimed territories, while the Taganrog and Shakhty districts went back to the RSFSR.

In 1954, First Secretary of the Communist Party of the Soviet Union Nikita Khrushchev transferred the peninsula of Crimea from the Russian SFSR to the Ukrainian SSR.

This event was viewed as an insignificant "symbolic gesture", as both republics were a part of the Soviet Union and answerable to the government in Moscow.

[citation needed][dubious – discuss] The island Tuzla Spit became a major dispute between Russia and Ukraine in 2003.

During the Soviet period, the island along with Crimea was transferred to Ukraine in 1954; the fact which was also fiercely contested by several Russian politicians was the legal background of the territorial change.

On the other hand, ships are impeded to travel to the east of the island (towards the Taman peninsula) due to the fact that there are shallow waters.

The intensity of the conflict increased due to the forecast of locations of oil and gas in the area and the lack of an established and ratified international border between Russia and Ukraine.

In December 2018, Russia announced it completed the construction of the 60-km barrier across Perekop Isthmus between Ukraine and Crimea.

[7] This refers to persons who are denied entry to Ukraine and members of units of the Russian armed forces or other law enforcement agencies, who try to cross the state border of Ukraine by any means beyond official checkpoints or at checkpoints without proper travel documents or documents containing inaccurate information.

[9][10][11] Ukraine claims this is a security measure to prevent Russia from forming units of “private” armies on Ukrainian soil.

It extends from a point in the Black Sea 22.5 kilometres (14.0 mi) south of the Kerch Strait, where the first contact the territorial waters of both states, is to the north of this strait, passing it is on the Sea of Azov to the point on the coast which goes to the land border and so on to the tripoint with Belarus to the north.

[citation needed] A treaty on the demarcation of the common border between the foreign ministers of Ukraine and Russia was signed on 17 May 2010 and came into force on 29 July of the same year.

[40] Since 16 March 2015, the Russia-Ukraine local border traffic agreement was unilaterally terminated by Ukraine citing national security.

[43] Simplified local border crossing was allowed for the 2015 Easter holidays in Stanytsia-Luhanska, Milove, Troitske, Novopskov and Bilovodsk raions of the Luhansk Oblast.