The United Kingdom will use its naval expertise to help Ukraine control the Black Sea as part of a 10-year security pact to be signed in the next few weeks.

According to The Telegraph, the memorandum of understanding promises to "keep Kyiv in the fight" against Russia by providing military support, focused on naval assets, financial assistance and intelligence sharing.

It will also contain promises of post-war security guarantees to deter Moscow if it decides to attack again, including increased arms supplies and the reimposition of sanctions.

The UK officials informed their Ukrainian counterparts that within the framework of the planned Memorandum of Understanding, the country will focus on strengthening Kyiv's maritime potential.

Military leaders have been very impressed by Ukraine's actions in the Black Sea, which have forced the Russian navy to retreat from its traditional base in occupied Crimea.

Some of the weapons, including Brimstone missiles, have come from the United Kingdom, which still has one of the most powerful navies in the world.

The new agreement will build on the recent announcement that the UK, together with Norway, will lead a "Maritime Capability Coalition" that will provide Ukraine with two mine-hunting vessels from the Royal Navy.

A source close to the negotiations said the agreement would demonstrate a commitment to supporting Ukraine in the fight: "They are also about providing assurances in a post-hostilities world to provide assistance should Russia then attack again."

The UK hopes to use its naval power and knowledge to build up the naval forces of Ukraine further.

The Royal Navy is already training Ukrainian demining specialists on unmanned submarines to disarm and defuse Russian bombs, booby traps and mines in its deep-water shipping lanes and prepare for amphibious assaults.

Last year, the UK began providing Ukrainian forces with shipboard versions of Brimstone missiles, which Russian military bloggers attribute to attacks on air defence systems in occupied Crimea.

At this stage, sources in the UK Ministry of Defence declined to share any details about the weapons that may be sent to Kyiv, other than to confirm that they will also include ground and air assets.