The U.S. is poised to announce that it will send Ukraine $350 million in weapons and equipment, U.S. officials said Monday, as fierce battles with Russian forces continue for control of the city of Bakhmut, and troops prepare for an expected spring offensive.

The latest package of aid includes a large amount of various types of ammunition, such as rockets for the High Mobility Artillery Rocket Systems, and an undisclosed number of fuel tanker trucks and riverine boats, according to the officials. Officials said it will be announced later Monday.

It comes as Chinese leader Xi Jinping arrived in Moscow on Monday, giving a political lift to Russian President Vladimir Putin against the West just days after an international arrest warrant was issued for the Kremlin leader on war crimes charges related to Ukraine.

Officials said the American aid will be taken from Pentagon stocks through the presidential drawdown authority, so it will be able to be delivered quickly to the warfront. The U.S. has provided more than $32.5 billion in military aid to Ukraine.

Officials spoke on condition of anonymity because the aid package has not yet been publicly announced.