Boston's mayor does not want marathon bombing suspect Tamerlan Tsarnaev buried in the city, an aide said.
Tsarnaev, 26, who lived in Cambridge, Massachusetts, was killed in a police shootout days after the April 15 bombings that killed three people and injured more than 260. His brother Dzhokhar, 18, remains imprisoned over the case.
Meanwhile, FBI director Robert Mueller discussed the bombings investigation with his Russian counterparts during a trip to Moscow and engaged in talks on security co-operation between the two countries.
FBI spokesman Michael Kortan said the visit was productive but would not elaborate on conversations in Moscow about the Boston bombing probe.
The US and Russia have been collaborating on the criminal investigation into the two suspects.
Russian agents placed Tamerlan Tsarnaev under surveillance during a six-month visit to southern Russia last year, then scrambled to find him when he suddenly disappeared after police killed a Canadian jihadist, a Russian security official said.
US law enforcement officials have been trying to determine whether Tamerlan Tsarnaev was indoctrinated or trained by militants during his visit to Dagestan, a Caspian Sea province that has become the centre of a simmering Islamic insurgency.
The Russian security official with the Anti-Extremism Centre, a government agency under Russia's Interior Ministry, said Russian agents were watching Tsarnaev and that they searched for him when he disappeared two days after the July 2012 death of the Canadian man, William Plotnikov, who had joined the Islamic insurgency in the region.