European Commission President Ursula von der Leyen embarks Friday on a tour of so-called frontline states to reassure them of Europe’s support against Russian aggression and bolster defense spending, a spokesperson for the EU executive said Thursday.

The tour will take von der Leyen to Finland, Estonia, Lithuania, Latvia and Poland — all countries that share a border with Russia or Belarus — as well as Bulgaria and Romania, in what amounts to her biggest diplomatic push on EU security and defense since the start of Russia’s full-scale invasion of Ukraine.

The lightning seven-country tour, lasting from Friday to Monday, coincides with ramped-up efforts by U.S. President Donald Trump to broker an end to Russia’s three-year-old war against Ukraine, which has killed tens of thousands of Ukrainians and forced millions to flee the country.

But despite a flurry of diplomatic activity in recent days, including a meeting between Trump and Vladimir Putin in Alaska, the Russian leader has shown little willingness to abandon his attacks against Ukraine. Overnight, Russian forces pummeled Kyiv with drones and ballistic missiles, killing at least 10 civilians and with one strike hitting an EU delegation building.

Commission spokesperson Arianna Podestà said Thursday: “The attacks [on the EU delegation building] are completely unacceptable. In no way will they shake our support for Ukraine.” She added that no diplomatic staff had been injured and that they would remain in Ukraine despite the attack.

The ongoing war has prompted a scramble to strengthen Europe’s militaries, with NATO’s European members pledging to ramp up defense spending to 5 percent of their gross domestic product by 2035.

But it remains unclear how EU countries, many of them grappling with high budget deficits, will manage to hit those targets. While the EU has made its spending rules more flexible to allow countries to borrow more easily on financial markets to boost defense spending, the total amounts available fall short of the astronomical increases demanded by Trump.

Von der Leyen’s tour kicks off on Friday in Latvia, where she will meet Prime Minister Evika Siliņa. She then heads to Helsinki where she will meet Finnish Prime Minister Petteri Orpo and President Alexander Stubb, according to the Commission.

On Saturday, the EU executive chief heads to Estonia to meet Prime Minister Kristen Michal before moving on to Poland for a meeting with Prime Minister Donald Tusk on Sunday. Later the same day, von der Leyen will be in Bulgaria to meet with Prime Minister Rossen Jeliazkov, before rounding out her trip on Monday with visits to Romania to see President Nicușor Dan and to Lithuania, where she will meet President Gitanas Nausėda.