Following a visit by United Nations Security Council envoys in January, UN's Secretary-General Ban Ki-moon is visiting Burundi to put pressure on President Pierre Nkurunziza.
Nkurunziza had flatly rejected a proposal by the UN to end months of violence in Burundi.
The central African nation is to host delegations from the UN and the African Union (AU) and also take part in a summit for heads of state of the East African Community at the end of February.
The United States' (US) special envoy to the Great Lakes region, Thomas Perriello, said Sunday that the summit is "a golden opportunity for the government of Burundi to show its seriousness about taking steps towards making a safe and secure environment for independent journalists, opponents and critics of the government, and for African Union monitors to be able to validate issues on the ground."
"There is a great opportunity for Burundi to take concrete steps to get back on the path to restore the foundations of Arusha [agreement] and peace and to restore relationships with many in the international community," Perriello said.
Violence out of control
Burundi tumbled into a political crisis in April 2015 after President Pierre Nkurunziza announced he would seek re-election for a third term, which he went on to win.
Opposition parties and civil society groups rejected the election, which resulted in a wave of protests, violence and even a failed coup. About 350 people are reported to have been killed.
The UN is under pressure to show it can halt the bloodshed in Burundi two decades after the 1994 genocide in neighboring Rwanda, where the ethnic Hutu majority were pitted against the Tutsi minority.
Accusations against Rwanda
Earlier, around 4,000 people took to the streets of Burundi's capital Bujumbura to condemn what the Burundian government called Rwanda's meddling in its affairs.
Speaking in Chibitoke province last week, Nkurunziza said "Rwandans and Burundians are brothers and neighbors" and should stop undermining the efforts of one another.
"We seize this opportunity to condemn the actions of those hiding in demonstrations to perpetuate acts of violence on behalf of Rwanda. Your actions are unnecessary, the messages only incite hatred between Rwanda and Burundi," Nkurunziza said.
In December 2015, the AU's Peace and Security Council announced plans to deploy a 5,000-strong force to intervene in Burundi.
Burundian leaders however rejected the proposal. The AU said it had appointed five heads of state to try to convince the government of Burundi to accept the peacekeeping force.
More pressure by international mediators
The UN said Secretary-General Ban will attempt to get Nkurunziza to accept the presence of international troops in Burundi. It's however not clear what the UN can do if Nkurunziza rejects this offer.
US envoy to the UN, Samantha Power, insisted, however, that the international community not back down from the peace talks.
"What Burundi needs urgently is an inclusive broadened mediation, and an expanded international presence ... we have a responsibility to try again and again to convince the president to stop rejecting offers of international support," Power said.
Haruna Nkunduwiga, a civil rights activist in Burundi, said Ban's visit will mark the immediate start of an inclusive dialogue.
"We believe Ban Ki Moon will put pressure on this country’s authorities to act in two steps. The first step is to quickly reinstate security and the second one is to urge the authorities to accept to sit down at the table and negotiate," Nkunduwiga said.
Apollinaire Niyirora in Bujumbura contributed to this report.