The WikiLeaks founder has been holed up at the embassy
to avoid extradition to Sweden, where prosecutors want to question him about sexual assault allegations.
Assange, an Australian,
has not been charged and has denied any wrongdoing in the Sweden case.
After years of diplomatic back-and-forth, Ecuador's foreign ministry says it will allow Swedish officials access to the embassy so they can question Assange.
"The attorney general's office notified the prosecutor of the kingdom of Sweden of its willingness to process the interrogation of Julian Assange," Ecuador's foreign ministry said in a statement.
A spokesman for the Swedish Prosecution Authority welcomed the announcement.
"This is a positive step and allows the investigation to continue," the spokesman said.
A date for the interview will be reached in "the coming weeks," the statement said. It did not provide details on how the questioning will be conducted.
Assange has been living in the embassy since July 2012, the same year Ecuador granted him political asylum.
He has said he fears Sweden would extradite him to the United States, where he could face the death penalty if he is charged and convicted of publishing government secrets through WikiLeaks
There are currently no charges filed against him in the US.
Swedish prosecutors have previously balked at questioning Assange at the embassy in London, arguing it should take place on Swedish soil.
Since WikiLeaks launched in 2006, it has published thousands of classified government documents, diplomatic cables and videos.
Just this month, Assange made headlines after WikiLeaks disclosed emails and voicemails from the Democratic National Committee.
Assange, who has vowed to release more information
to damage Hillary Clinton's campaign, has been making media rounds via satellite from the Ecuadorian embassy in London.
For years, WikiLeaks has released sensitive government documents. In 2007, it posted a procedures manual for Camp Delta, the US detention center in Guantanamo Bay
Three years after that, the site posted more than 90,000 classified documents related to the war in Afghanistan
. It was described as the biggest leak since the Pentagon Papers during the Vietnam War
WikiLeaks has also published almost 400,000 classified military documents from the Iraq war
, providing insights on how many Iraqi civilians have been killed and many accounts of abuse by Iraqi's army and police.