KYIV — Ukraine has begun defending territory with long-range ballistic missiles secretly provided by the United States, US officials have confirmed.

The weapons were part of a $300m ($240m) aid package that was approved by US President Joe Biden in March, and arrived this month.

They have already been used at least once to strike Russian targets in occupied Crimea, US media report.

It is not clear how many of the weapons have been sent to Ukraine.

The US had previously supplied Ukraine with a mid-range version of the Army Tactical Missile Systems (ATACMS) but had been reluctant to send anything more powerful, partly over concerns about compromising US military readiness.

However, Biden is said to have secretly given the green light to send the long-range system —which can fire missiles distances of up to 300km (186 miles) — in February.

“I can confirm that the United States provided Ukraine with long-range ATACMS at the president’s direct direction,” State Department spokesman Vedant Patel said.

He added that the US “did not announce this at the onset in order to maintain operational security for Ukraine at their request”.

The longer-range missiles were used for the first time last week to strike a Russian airfield in occupied Crimea, Reuters quoted an unnamed US official as saying.

And the new missiles were also used in an attack on Russian troops in the in the port city of Berdiansk overnight on Tuesday, the New York Times reported.

Kyiv has recently stepped up its calls for Western assistance as Russia makes steady gains in its invasion.

News of the weapons shipments comes after Biden signed a new $61bn military aid package for Ukraine into law following months of congressional gridlock.

“Now we will do everything to make up for half a year spent in debates and doubts,” Ukrainian President Volodymyr Zelensky said of the newly approved aid.

“What the Russian occupier was able to do during this time, what Putin is now planning, we must turn against him.”

Zelensky recently warned that a full-scale Russian offensive is expected in the coming weeks after Ukraine’s loss of the city of Avdiivka during the winter.

Ukrainian officials have previously blamed recent delays in military aid from the US and other Western allies for the loss of lives and territory in the war. — BBC