Speaking ahead of an EU foreign ministers' meeting in Brussels, where the war in Ukraine was the main topic, Kallas argued that pressure on Moscow should be increased, not reduced.
"Russia has shown it does not really want to negotiate and is in fact intensifying its attacks on Ukraine," she said.
"We see the easing of sanctions on oil, on Russia, by the US is a dangerous precedent because right now we need them to have less money for waging the war than more."
Kallas called on EU members to adopt a 20th package of sanctions targeting Russia's so-called shadow fleet and to approve a EUR 90 billion loan for Ukraine.
Both measures are currently being blocked by Hungary.
The Middle East was also on the meeting's agenda.
Kallas warned that the closure of the Strait of Hormuz would ultimately benefit Russia, adding that developments in the region were affecting Ukraine and other partners alike.
Ministers gathered in Brussels for a full day of talks covering European security strategy, Ukraine, the Middle East and the EU's southern neighbourhood.
They were set to hold a video call with Ukrainian Foreign Minister Andrii Sybiha, and expected to be joined at lunch by Indian Foreign Minister Subrahmanyam Jaishankar for informal talks on bilateral relations.
Representing Poland was Deputy Prime Minister and Foreign Minister Radosław Sikorski.
(ał/gs)
Source: IAR