Former President Barack Obama arrived at 10 Downing Street in London Monday for an “undisclosed private meeting” with UK Prime Minister Rishi Sunak.

The Democrat waved to reporters outside the prime minister’s residence before entering the building. Downing Street officials have refused to disclose what Obama and Sunak were meeting to discuss, the Independent reported.

His one hour visit was said to be a courtesy call as he was in London for some work engagements linked to the Obama foundation.

Obama’s visit came amid “trans-Atlantic tensions over the Ukraine war” and fears that Donald Trump could win another term in the White House and scale back support for Ukraine, the Standard reported.

Republicans are currently blocking the latest aid package for Ukraine.

White House deputy press secretary Andrew Bates told Fox News Monday that Obama and Biden have a close “personal bond” and agree “overwhelmingly on the issues facing the country, including building an economy that works from the bottom-up and middle-out, protecting our critical freedoms, and opposing attacks on our democracy.”

“There are no stronger supporters of President Biden’s leadership and agenda than President Obama, his team, and alumni of the Obama-Biden Administration – many of whom serve during this presidency,” he said. “And the President talks to both former President Obama and President Clinton often.”

Bates made the remarks in response to recent reports that a rivalry exists between Biden and Obama.

According to Axios, Biden often compares himself to the former president “when speaking about a perceived accomplishment.”

“Obama would be jealous,” Biden has reportedly bragged in the past.

“We recognize that the actual level of drama in this White House is insufficient to meet some reporting quotas, but President Biden does not make such comments in private,” Bates said. “As President Biden has said, President Obama is family to him.”