Russia forces targeted Ukrainian emergency responders with a deadly double-tap attack,Ukrainian officials said,wounding two responders in the northern region of Chernihiv.

The overnight attack on September 21 was the second time in a week that Russian forces hit firefighters in the region who were responding to an earlier missile or drone attack,said Vladislav Chaus, the regional military administrator.

Overnight, Russia launched nearly six dozen drones at targets across Ukraine,military officials said,one of the smallest barrages in weeks.

In recent months, Russias drone-and-missile attacks on Ukraine have included hundreds of projectiles, often overwhelming Ukrainian defenses.

In his overnight address, Ukrainian President Volodymyr Zelenskyy urged the United States to impose strong measures against Russia amid surging tensions among NATOs easternmost members.

Zelenskyy also repeated his stance that he is ready to meet with Russian President Vladimir Putin, who so far has rejected a summit on neutral ground.

SEE ALSO:

Zelenskyy Calls For 'Strong' US Measures Against Russia As Tensions Rise With NATO

Trump, who has long expressed admiration for Putin, has voiced frustration with the Kremlin leader's refusal to accept a cease-fire and his rejection of direct talks with Zelenskyy.

"He's really let me down," Trump said during a visit to London on September 18.

Washington and European allies have already imposed financial measures on Moscow following its February 2022 full-scale invasion with a view to crippling the Russian economy, but Kyiv and its supporters are seeking more action.

The overnight strikes came shortly after NATO countries voiced outrage at a Russian incursion into Estonian airspace on September 19, as well as recent Russian drone incursions into Poland and Romania.

NATO must respond forcefully to Russian violations -- including potentially by shooting down Russian jets, Czech President Petr Pavel said.

Estonia on September 18 said three Russian warplanes encroached into its airspace and lingered for 12 minutes, prompting other NATO members to scramble their jets. The Kremlin has denied the incident, saying the jets were over international waters.

SEE ALSO:

Estonia Seeks To Invoke NATO Article 4, As EU Plans New Round Of Russian Sanctions

Estonia said it had requested Article 4 consultations of the alliance.

For its part, Ukraine has conducted a weeks-long drone campaign, that has targeted Russian oil infrastructure, which has helped drive up the price of gasoline nationwide.

In the Belgorod border region, one woman was killed when a Ukrainian shell hit a house, regional Governor Vyacheslav Gladkov, said in a post on Telegram.

Russias military said at least 65 Ukrainian drones were launched at Russia targets overnight on September 20-21.