Lebanon officially asked the European Union on Thursday not to add Hezbollah to its blacklist of terrorist organisations, calling the militant group an "essential component of Lebanese society".
The request came on the same day Bulgaria marked the first anniversary of a deadly attack on an Israeli tourist bus at a Black Sea resort and called for sanctions against Hezbollah, suspected of being behind the bombing.
It also came as EU foreign ministers prepared on July 22 to discuss whether to add the military wing of Hezbollah to their list of terrorist groups.
A Lebanese presidency statement said it had "asked the foreign minister to notify the European Commission and member states of the government's request, and not to place Hezbollah, an essential component of Lebanese society, on the list of terror organisations".
It asked that "any decision not be taken in a precipitate manner, and without being based on objective and irrefutable proof".
The Shiite Muslim movement is a major political force in multi-confessional Lebanon, and has a strong presence in the outgoing government of Prime Minister Najib Mikati.
Last July 18, five Israeli tourists and the Bulgarian driver of their bus were killed in a bombing at Burgas airport in the deadliest attack on Israelis abroad since 2004.
Bulgaria pointed the finger at the Iran-backed Hezbollah.
The bus was carrying a group of more than 40 Israeli tourists after they had just arrived in the country.
A year later, investigators are increasingly frustrated in their efforts to track down those responsible.
After the attack Israel immediately blamed Iran, which denied complicity, and its "terrorist proxy" Hezbollah for the bombing.
"There are clear links to Hezbollah behind this attack," Bulgaria's Interior Minister Tsvetlin Yovchev said on Thursday, citing new information from foreign intelligence services.
Both the United States and Israel have long demanded that the European Union list Hezbollah as a terrorist group.
But despite strong pressure to follow their example, the EU had until last month skirted an issue seen as sensitive and divisive, with Britain openly in favour but France and Italy reluctant.
After months of hesitation, counter-terrorism specialists from the bloc first met on the issue on June 4 but failed to reach unanimity on blacklisting Hezbollah.