U.S.-made Abrams tanks have arrived in Ukraine, President Volodymyr Zelenskiy said on Monday.

"Good news from Minister (of Defence Rustem) Umerov. Abrams are already in Ukraine and are being prepared to reinforce our brigades," he said on the Telegram messaging app.

He did not say how many of tanks had arrived.

The jet-powered American tanks were a top demand from Ukraine until Washington finally offered more than 30 of them in January. European countries have already sent dozens of German-made Leopards and some British Challengers.

The delivery comes nearly four months into Ukraine's big offensive to recapture Russian-occupied territory. Kyiv has reported slow, steady progress so far, capturing villages and ground that it says improves its position, but has yet to force a major Russian retreat as it did three times last year. Moscow says the Ukrainian offensive has already failed.

"I am grateful to our allies for fulfilling the agreements! We are looking for new contracts and expanding our supply geography," Zelenskiy added.

U.S. President Joe Biden said last week that the first American Abrams tanks would be delivered to Ukraine this week.

(Reporting by Anna Pruchnicka Editing by William Maclean and Peter Graff)