"We're absolutely convinced that previous constraints are gone. Even Chancellor Angela Merkel mentioned that and she didn't fear possible criticism of the press," Lourenco told DW. 

He was speaking at the end of a two-day visit to Berlin, on the invitation of the chancellor, during which he met with Merkel and representatives of German companies doing business in Angola.

After discussions with Lourenco on Wednesday, Merkel told reporters at a joint press conference she remembered the old controversy over supplying naval vessels to Angola but was open to discussing defense matters.

In 2011, Merkel's ruling coalition came under fire from the opposition over her plan to supply German-built naval vessels to Angola and the deal had to be scrapped. 

'Germany will support shipyards'

"It might be that certain investments on the Angolan side materialize and then, naturally, we would gladly partner when it comes to such investment decisions by the Angolan navy," Merkel said.

Lourenco, in the interview with DW the next day, said because the constraints were gone, "Germany will support shipyards in Kiel, which are presumably the ones that are going to supply those ships to Angola."

Angola has said it needs the German-built naval vessels to protect its maritime frontier from pirates and terrorists.

Lourenco's government is facing criticism over its spending. Luanda has set aside 21 percent of its entire budget for defense, 11.3 percent for education and 7.4 percent for health.

Read more: Economic reforms could make Angola attractive

Courting Europe

"We are seeing a country that is more concerned with spending millions on a satellite than to buy medicines to fight malaria," Raul Danda, the vice president of the main opposition party, Union for the Total Independence of Angola (UNITA), told DW.

"We are seeing a government more concerned with setting dates and marketing abroad than solving the real problems of the country."

Lourenco's two-day visit to Berlin comes after similar visits to court investors in France and Belgium in the year since he was chosen to succeed Jose Eduardo dos Santos, who had been president for 38 years.

Read more: Jose Eduardo dos Santos era ends as polls open in Angola

His Berlin visit included talks with representatives of German companies doing business in Angola and assurances that Angola has become investment-friendly.

Luanda is also under pressure to root out endemic corruption and criticized over the manner in which it is trying to go about it.

Lourenco told DW Angola was seeing progress in this regard already as a result of its policies and "courage" in fighting corruption.

"It isn't easy because there are people on the other side who are interested in stopping us – something that won't happen," he said.

Corruption "witch hunt"

"The international community has already seen that what we have said is serious, that we're not joking, and we're getting positive signals. So, we succeeded with the issuing of Eurobonds, and, more recently, the IMF (International Monetary Fund) signaled it would be open for a financing agreement," Lourenco said.

Danda, however, accused Lourenco of conducting a "witch hunt."

"What President Joao Lourenco has been doing so far is exonerating and naming people, and we are not seeing much more. It is true that people are being investigated, but I think he is turning it into a witch hunt," he said.

Many others in Angola who had become "illicitly enriched" were not being held accountable, according to Danda.

"We continue to see those lower-level people being put in jail. This is a show-off scam," he told DW.

Danda said he did not understand how anyone outside of Angola can believe Lourenco is doing anything extraordinary.

"He is not. It is because he is not yet president of the (ruling) MPLA (People's Movement for the Liberation of Angola). It's a question that will only be answered in a few days. With the MPLA, one person leaves and another enters, but the system remains the same."

Lourenco's predecessor dos Santos is due to step down as MPLA leader in September.

Thiago Melo da Silva contributed to this report.