The Swiss Federal Council authorized the security procedures Friday, which also entail air surveillance by the nation’s air force and the deployment of up to 1,000 troops. Col. Monica Bonfanti of the Geneva police said during a news conference that 900 additional police officers from other regions would aid Geneva’s existing forces, bringing the total up to 2,000 for the summit.

“Switzerland is obliged to ensure the protection of persons who enjoy special protection under international law, such as the American and Russian heads of state,” the Federal Department of Defense said.

Stephane Theimer, vice director of the Federal Office of Police and Federal Security Service head, said that the office hadn’t received word of any specific danger to the summit, but “the terrorist threat remains high in Switzerland and Europe.”

For more reporting from the Associated Press, see below.

“Naturally, the respective diasporas of the two countries could want to take advantage of the visit of their president to carry out actions,” Theimer said. “We are at a high level (of alert).”

Elaborating on his comments to The Associated Press, he said the meeting offered a “window of opportunity” for opponents/

“For the moment we don’t have any concrete sign when it comes to actions by the diaspora, but it’s something we’re taking into consideration,” Theimer said.

The extra troops will have roles in the protection of foreign emissaries and support for Geneva regional police in the air and on Lake Geneva, the defense department said.

Local authorities announced Thursday that the summit, part of Biden’s first overseas trip as president, will take place in an 18th-century manor house in a public park that looks out onto the lake.

The White House has played down expectations for the summit and said Biden plans to raise Ukraine, arms control, human rights and cyber ransomware attacks with Putin.

Russian officials have said their summit agenda includes strategic stability, global crises, climate change and efforts to counter the coronavirus pandemic.