Julian Assange, the WikiLeaks founder, has lost some of his guest privileges at the Ecuadorean Embassy in London. After shielding the Australian anti-secrecy activist for more than four years from potential prosecution in Sweden, where he faces sexual assault charges, Ecuador cut off Mr. Assange’s access to the internet over the weekend, according to WikiLeaks.

In a tweet, WikiLeaks said Secretary of State John Kerry pressured Ecuador’s foreign minister last month to prevent Mr. Assange from disclosing more emails involving Hillary Clinton. A State Department spokesman called the allegation “simply untrue.”

The Ecuadorean government confirmed it had restricted internet access at the embassy, saying it “respects the principle of nonintervention in the internal affairs of other states.” It also said Mr. Assange’s asylum status was unchanged. When Quito offered him refuge in June 2012, the government of President Rafael Correa saw an opportunity to rankle Washington, which he and other leftist leaders accuse of undermining their socialist governments. But relations between the United States and Ecuador have warmed up somewhat in recent years.