WASHINGTON (Reuters) - U.S. House of Representatives Speaker Mike Johnson combined praise for NATO with a call for members to meet their targeted annual spending of at least 2% of GDP on defense in his first major foreign policy speech as the chamber's Republican leader.

"I just want to say this, and I'll deliver the message to them emphatically: Republicans, of course, celebrate the peace and prosperity that NATO has secured and will continue to stand by our partners as we prevent needless wars," the Republican House leader said at the Hudson Institute think tank.

"But we also believe that NATO needs to be doing more," he said, as members of the military alliance gathered for this week's summit in Washington, which will include meetings with members of the U.S. Congress.

Johnson also took a hard line on China, calling it "our single greatest threat... engaging in malign influence operations around the world."

He said the House will vote on a series of bills to counter China this year, including beefed up sanctions and efforts to clamp down on trade policies seen as harmful to U.S. interests.

Defense spending by NATO members has become a highly contentious issue in recent times as former President Donald Trump accuses Europeans of spending too little on their own security and relying on Washington for protection.

Earlier this year, Trump - the Republican candidate in the Nov. 5 U.S. presidential election - sparked outrage by suggesting he would not protect NATO members that failed to spend enough on defense and would even encourage Russia to attack them.

Johnson is a close ally of Trump and, as speaker, sets the legislative agenda for the House.

Months after Democratic President Joe Biden asked the House to approve funding for Ukraine, Johnson changed course this year to allow the House to vote on - and pass - billions of dollars in additional aid to the country.

Johnson said people have come up to him at events all over the country and thanked him for passing the funding. "People understand that (Russian President Vladimir Putin) would not stop if he took Kyiv. He's a ruthless dictator in my view," Johnson said.

NATO Secretary General Jens Stoltenberg said last month that more than 20 NATO members will meet the alliance's target of allocating at least 2% of GDP to defense this year, compared with fewer than 10 members five years ago.

(Reporting by Patricia Zengerle, editing by Deepa Babington)

By Patricia Zengerle