Ukraine urged NATO on Wednesday to prepare economic sanctions on Russia and boost military cooperation with Kyiv as the country joined the Western alliance for talks about how to deter Russia from a renewed attack after it massed troops close by.

Ukraine, a former Soviet republic that now aspires to join the European Union and NATO, has become a potential flashpoint between Russia and the West as relations have soured to their worst level in the three decades since the Cold War ended.

“We will call on the allies to join Ukraine in putting together a deterrence package,” Ukraine’s foreign minister, Dmytro Kuleba, told reporters as he arrived for talks with his NATO counterparts in Riga.

As part of this package, NATO should prepare economic sanctions against Russia in case it “decides to chose the worst-case scenario”, he said, adding that the alliance should also boost military and defence cooperation with Ukraine.

“We are confident that if we join efforts, if we act in a coordinated fashion, we will be able to deter President Putin and to demotivate him from choosing the worst-case scenario, which is a military operation,” Kuleba said.

Danish Foreign Minister Jeppe Kofod told reporters upon arrival for the NATO session that any military operation that would violate the sovereignty of Ukraine would be met with “severe consequences” and that Denmark was ready to engage with “heavy” sanctions.

His comments echoed those of NATO and the United States, who on Tuesday issued stark warnings to Russia that it would pay a high price for any new military aggression against Ukraine.

“Any future Russian aggression against Ukraine would come at a high price and have serious political and economic consequences for Russia,” NATO Secretary-General Jens Stoltenberg told reporters after the first day of talks between the 30 allies in Riga.

Russia’s President Vladimir Putin countered that Russia would be forced to act if U.S.-led NATO placed missiles in Ukraine that could strike Moscow within minutes.

U.S. Secretary of State Antony Blinken said he would have more to say on the issue on Wednesday after consulting with NATO allies.

Blinken is scheduled to give a news conference at 1345 GMT.

The Kremlin annexed the Black Sea peninsula of Crimea from Ukraine in 2014 and then backed rebels fighting government troops in the east of the country. The conflict has killed 14,000 people, according to Kyiv, and is still simmering.

Kuleba also warned against a recognition of Crimea by Belarus, a close Russia ally, after Belarusian leader Alexander Lukashenko said the Crimean Peninsula was legally Russian territory, RIA news agency reported, in a reversal of his public stance. 

“The potential recognition of the occupied Crimea by Belarus will be a point of no return in our bilateral relations, and we will act respectively. Because for us, Crimea is not a field for compromises,” Kuleba added.