Angola's president has said ties with former colonial ruler Portugal are "not well", amid tensions over Lisbon's investigation of Angolan officials.
Jose Eduardo Dos Santos said "the current political climate" was not conducive to building a strategic relationship.
He said that Western nations fed the perception that "a rich African man is corrupt".
Portugal's government has expressed "surprise" at the remarks.
It said it had been working hard to foster relations, citing what it said were the "special ties that unite the two peoples" and the strategic importance of good relations for both sides.
Last week, Portugal's Foreign Minister Rui Machete was called before a parliamentary committee in Lisbon after he expressed regret in an interview in Angola about a corruption probe by Portuguese prosecutors that was said to involve top Angolan officials.
The BBC's Alison Roberts in Lisbon says some in Portugal saw his comments as kowtowing to Angola's growing power while infringing judicial independence.
Portuguese opposition parties called for Mr Machete to resign.
Angola's state-run Jornal de Angola newspaper then published a scathing editorial dismissing Portugal's elite as ignorant and corrupt.
Even so, observers in Lisbon were taken aback by President dos Santos's decision to join in the criticism, our reporter says.
The Angolan officials being investigated in Portugal have not been named.
But Angola's Minister for External Relations, Georges Chicotty, denied that President Dos Santos' comments were directly linked to the legal probes in Portugal.
"We don't intervene in any Portuguese political issues," he told BBC Focus on Africa programme.
However, Mr Chicotty added: "We have right now 250,000 Portuguese living in Angola, doing businesses. And none of them has ever been prosecuted or investigated whatsoever. I think that's the balance that you need."
BBC Angola expert Zenaida Machado says that President Dos Santos' comments show that Luanda now feels strong enough to stand up to its former colonial master.
Angola and Portugal are major trading partners, with many investors from oil-rich Angola buying stakes in Portuguese companies.
Angola's economy is continuing to grow, although more slowly than predicted this year.
Meanwhile, debt-ridden Portugal has been hit hard by the continuing eurozone financial crisis. The government has been trying to introduce a wide range of reforms after agreeing a multibillion bailout.
In 2011, Angola offered Lisbon its help to cope with the crisis.
Despite its growing economy and the huge wealth of a tiny elite, most Angolans live on about $2 (£1.25) a day.