"The situation with the Astravyets sanctions is very bad because we are late with the procedures," the website cited Asta Skaisgiryte, the president's chief foreign policy adviser, as writing.
"As to fertilizers, we will first get losses for our business, and then the Russians will take over the Belarusian enterprise. Let's try to defend the interests of LT (Lithuania)!"
"We are not trying to block all sectoral sanctions; we just want fertilizers out, the ANPP (Astravyets nuclear power plant) in," said another person who signed the internal correspondence quoted by Delfi only with her first name, Skirmante.
According to the website, it was likely Skirmante Straigiene, an advisor in the president's foreign policy team.
A few days after the correspondence, Darius Kuliesius, Nauseda's chief national security advisor, said publicly that the president would support an EU deal on sectoral sanctions against Belarus, whether or not it included fertilizer exports.
In a reply sent to Delfi, the president's office said that the fragments of internal correspondence did not reflect the final common position agreed with the government.
The Foreign Ministry did not comment on Delfi's report.
The correspondence took place at a time when the EU was to decide on bans on oil product and fertilizer imports from Belarus. The EU eventually decided to impose sanctions on some products, but not on existing contracts.
US sanctions against Belaruskali came into force on December 8, but its product shipments via Lithuania did not stop, because Belarus' potash giant had made advance payments to Lietuvos Gelezinkeliai (Lithuanian Railways, LTG) back in November.
The Lithuanian government says that the US sanctions do not directly apply to the transit of fertilizers through Lithuania.
However, the government announced last week, after the sanctions had already taken effect, that it was seeking to terminate the state railway company's contract with Belaruskali.
Foreign Minister Gabrielius Landsbergis and Transport Minister Marius Skuodis have handed in their resignation letters over the Belaruskali scandal.