French Presidential candidate Marine Le Pen may soon be find herself barred from travelling to Ukraine, after making comments that appeared to legitimise Russia's annexation of Crimea.

The Ukrainian security service SBU has sent a letter to the foreign ministry to agree on the terms of the ban, which may last for up to five years, the Ukrainian news agency UNIAN reported on 4 January.

The foreign ministry also issued a statement, alluding that Le Pen "shows disrespect for the sovereignty and territorial integrity of Ukraine and completely ignores the fundamental principles of international law."

"In this regard, we remind that such statements and actions in violation of the Ukrainian legislation will necessarily have consequences, as it was in the case of certain French politicians, who are denied entry to Ukraine," the statement read, quoted by Reuters.

The leader of the far-right party National Front, who will run in the upcoming presidential elections this spring, was interviewed on French television on 3 January. While the conversation primarily focused on Le Pen's policy proposals concerning the economy, EU relations and migration, it eventually reached foreign policy, and in particular the relationship with Russia.

When she was asked explicitly if she thought the annexation of Crimea was illegal, she said "I absolutely do not think the annexation was illegal. There was a referendum".

Marine Le Pen invitée de « Bourdin Direct » sur RMC et BFM-TV ...

Marine Le Pen était ce matin l'invitée de Jean-Jacques Bourdin sur RMC et BFM-TV :

Posted by Marine Le Pen on Tuesday, January 3, 2017

Ukraine has always disputed the legality of the referendum, which was also declared illegal by the United Nations General Assembly. Both the European Union and the United States imposed sanctions on Russia as a consequence of the annexation, but political support for the restrictions may also be waning.

Another French presidential candidate, the centre-right former prime minister Francois Fillon, is seen as a Russian sympathiser as he favours lifting the sanctions. In the US, people close to President-elect Donald Trump have hinted that the sanctions policy may change once he takes office.