Boris Johnson was interested in having a strong EU and a strong Slovenia within the bloc. Johnson and his host, Foreign Minister Karl Erjavec, want the two countries to further deepen ties in the future.

The pair hailed relations between Slovenia and Britain, whose 25th anniversary will be marked later tonight with a special reception that the British Embassy is organising at the National Gallery.

Erjavec, who noted he had also acquainted Johnson with the border arbitration situation with Croatia, said one of the topics discussed were the Western Balkans. The pair established they are "not very happy with the situation in the region".

"We know about the situation in Macedonia, we know about the complications in the negotiations between Serbia and the EU and things are also not the way we would like them to be in Bosnia," he said.

Erjavec said Johnson and him agreed the key thing was that these countries preserve the prospects of EU and NATO membership.

Returning to bilateral relations, Erjavec pointed out that trade between the two countries had increased by 18% in the past two years and both called for cooperation to be strengthened further in the future.

Johnson also spoke of very important areas of political cooperation, saying "we are very conscious of the role that Slovenia has had to play at the front of the challenge that we all face as Europeans in migration...the challenge we face working together to combat extremism and terrorism".

The British foreign secretary meanwhile reiterated that Britain would definitely trigger Article 50 of the Lisbon Treaty and thereby leave the EU, but it would not leave Europe.

"We don't want Europe in any way to get weaker or to break up. On the contrary, we want to be supportive...We believe in a strong UK, a strong EU and a strong Slovenia within the EU," Johnson said.

Before attending the ceremony, organised 25 years after Britain recognised independent Slovenia, Johnson also met Prime Minister Miro Cerar and President Borut Pahor.

Cerar and Johnson also agreed political, economic and cultural cooperation was at a very high level, while calling for even closer ties, especially in business, Cerar's office said.

They moreover expressed their expectation that Brexit would be conducted in a constructive way, "with the preservation of friendly ties and deeper cooperation among the countries also in the future".

Meanwhile, Johnson said at the ceremony that he had last been in Slovenia as a reporter in 1991 when some wished to prevent Slovenia's independence. He is happy they failed, as Slovenia's story is a success story, a story of a dynamic, open, modern European country.

Britain recognised Slovenia on 15 February 1992 and on this day Slovenia opened an embassy in London and Britain an embassy in Ljubljana.

"Slovenia will never forget this gesture by Great Britain, the fact that it recognised it as an independent country," Erjavec said, arguing this opened the door to membership in the UN, the OECD, NATO and the EU.