Speaking to Italian broadcaster RAI during a visit to Rome, Sikorski argued that Ukraine had defied early expectations.
Russia had anticipated to win the war in three days, he said, yet now with the invasion in its fifth year, Moscow had still not achieved its objectives while its economy was faltering.
Ukraine, meanwhile, had struck Russian refineries and arms factories at ever greater distances and built a modern defence industry producing "millions of drones".
He said that "in Poland at least", Ukraine was seen as an increasingly significant security actor.
Sikorski was particularly pointed about Orbán, whose Fidesz party lost Hungary's parliamentary election earlier this month.
He accused the outgoing prime minister of repeatedly telling US President Donald Trump that Ukraine was a lost cause and that Russia always won – claims Sikorski dismissed as "historically untrue".
The Polish foreign ministry also criticised Orbán for blocking EU loans to Ukraine, sanctions on Russia and accession talks with Kyiv.
On defence spending, Sikorski acknowledged that some European countries had historically underspent on defence, saying Trump had been right to raise the issue.
He noted that Poland currently spends 4.8 percent of its GDP on defence, and that European allies had committed at last year's Hague summit to double their spending further.
He also pushed back on criticism of NATO, describing the alliance as a defensive body rather than a global police force, and said Poland remained a committed ally with American troops stationed on its soil.
(ał)
Source: PAP