NATO summit to demonstrate trans-Atlantic unity: Secy Gen

"This summit will be a strong demonstration of trans-Atlantic unity of Europe and North America, because we are stronger and safer together in the more unpredictable world," dpa news agency quoted Stoltenberg as saying on Monday. 

Among the range of different challenges and threats to prepare for, Stoltenberg cited Russia, with its growing aggression toward its neighbours, and China as it invests in new military capabilities. 

Biden is due to attend the June 14 meeting of leaders of NATO member states as part of his first foreign trip as President. 

Stoltenberg said he was pleased to receive Biden in Brussels. 

"A strong NATO is good for Europe, but it's also good for the US, no other major power has so many friends and allies as the US has in NATO." 

White House Spokesperson Jen Psaki said that, during the meeting, Biden "expressed his strong commitment to working closely with Allies to build on NATO's seven decades of success safeguarding trans-Atlantic security and democratic values". 

"The two leaders agreed on the importance of the NATO 2030 initiative to adapt the Alliance to meet the challenges of strategic competition and transnational threats, including climate change and cyberattacks." 

Under former President Donald Trump, relations between the US and many of its allies became strained. 

Biden has pledged to address this. 

Stoltenberg also met US Defence Secretary Lloyd Austin on Monday. 

The issues they discussed included Afghanistan, where the official withdrawal of international troops has been underway for just over a month.