Ukraine and the UK on Thursday signed a "100 Year Partnership" agreement to deepen defense cooperation and address long-term threats and challenges to maritime security after British Prime Minister Keir Starmer arrived in the capital Kyiv for his first visit since taking office last year, according to Anadolu Agency.

“Today is a truly historic day. Relations between Ukraine and the UK are closer than ever,” state news agency Ukrinform quoted Ukrainian President Volodymyr Zelenskyy as saying.

Zelenskyy said the relationship between his country and the UK has reached a new level, describing the agreement as "more than a strategic relationship."

The agreement was signed during Starmer's unannounced visit to Kyiv.

The agreement, published by Ukraine's Presidential Office, will deepen defense cooperation between the two countries while also addressing long-term threats and challenges to maritime security.

It will strengthen cooperation in areas such as economics and trade, energy, climate change, and clean energy transitions.