Britain is considering sending additional anti-ship missiles to Ukraine, beyond the weapons it has already promised, Defence Secretary Ben Wallace said on Wednesday.

NATO defence ministers are meeting in Brussels later on Wednesday and will discuss on the sidelines possible additional delivery of weapons to Ukraine.

Wallace said that delivery of guided multi-launch rocket systems (MLRS) Britain has promised to Ukraine would be "imminent" and that London was considering sending more weapons.

"We are obviously exploring anti-ship capabilities greater than we already put, in the Brimstone family of weapons systems," he told reporters during a visit to Oslo.

"We are (also) looking at whether we can donate to complement the Dutch and the Danish (with) our Harpoons as well, although they are a slightly different variant," he added. Harpoons are anti-ship missiles.

Training of Ukrainian military personnel was becoming as important as sending weapons, he said, and more was needed to be done in terms of training.

"The Ukrainian forces in the east of the country ... Some of them have been on that front for 90 days, they are exhausted, they are often, in artillery terms, outnumbered in very high ratios."

"It is important to help Ukraine with its ability to replace people on the frontline," Wallace said.

He said he would also be going to Turkey next week to discuss Islamic State and Syria, Sweden's and Finland's NATO applications - which Ankara opposes - as well as exports of grain from Ukraine.

Britain sees Turkey as a possible guarantor of any deal for shipping channels to get grains out of Odesa.

On Sweden's and Finland's NATO application, Wallace said it was "important" to listen to Turkey's concerns. (Reporting by Gwladys Fouche Editing by Stine Jacobsen and Peter Graff)