NATO Secretary- General Jens Stoltenberg speaks during a news conference prior to a NATO summit in Brussels on Monday. Olivier Matthys/Associated Press

BRUSSELS — NATO allies will decide at a summit this week to increase the strength of their rapid reaction force nearly eightfold to 300,000 troops as part of their response to an “era of strategic competition,” the military alliance’s secretary-general said Monday.

The NATO response force (NRF) currently numbers around 40,000 soldiers which can deploy quickly when needed.

Coupled with other measures including the deployment of forces to defend specific allies, NATO Secretary-General Jens Stoltenberg said the move is part of the “biggest overhaul of collective defense and deterrence since the Cold War.”

“These troops will exercise together with home defense forces,” Stoltenberg said. “And they will become familiar with local terrain, facilities, and our new pre-positioned stocks. So that they can respond smoothly and swiftly to any emergency.”

In response to the Kremlin’s decision to start the war, U.S. President Biden and his NATO counterparts agreed in February to send thousands of troops, backed by air and naval support, to protect allies near Russia and Ukraine. The 30-nation organization decided at the time to send parts of the NRF and elements of a quickly deployable spearhead unit to the alliance’s eastern flank, marking the first time the force had been used in a defense role.

Stoltenberg made the remarks at a press conference ahead of a NATO summit this week in Madrid when the 30 allies are expected to also agree on further support to Ukraine in its war against Russia.

Stoltenberg said he expects allies to make clear they consider Russia “as the most significant and direct threat to our security.” At the summit, allies will also decide to strengthen their battlegroups on NATO’s eastern flanks, he said.

In NATO’s new strategic concept, the alliance is also set to address for the first time the security challenges posed by China, Stoltenberg said. In Madrid, allies will discuss how to respond to the growing influence of Russia and China in their “southern neighborhood,” he added.

Stoltenberg said allies will agree to deliver further military support to Ukraine when they convene in Spain, with NATO members set to adopt a “strengthened comprehensive assistance package,” including deliveries of secure communication and anti-drone systems.

Over the long term, Stoltenberg said allies aim to help Ukraine transition from Soviet-era armaments to modern NATO equipment. The world’s seven leading economic powers underscored Monday their commitment to Ukraine for “as long as it takes.”

Another central theme at the NATO summit will be the possibility for Finland and Sweden to join the alliance following Russia’s invasion of Ukraine.

NATO member Turkey has so far blocked the applications, citing what it considers to be the two countries’ soft approach to organizations Turkey considers to be terrorist, such as the Kurdistan Workers’ Party, or PKK.

Stoltenberg said that Turkish president Turkish President Recep Tayyip Erdogan, Finnish President Sauli Niinisto and the Swedish prime minister Magdalena Andersson have agreed to meet Tuesday on the sidelines of the summit.

Officials from the three countries have stepped up talks ahead of the NATO gathering in a bid to break the deadlock.

“My strong hope is that this dialogue can be successful and concluded in the near future, ideally before the summit,” Andersson said after talks with Stoltenberg in Brussels.

Turkey is demanding that Sweden and Finland grant extradition requests for individuals who are wanted by Turkish authorities. Ankara claims the countries are harboring PKK members as well people it says are linked to a failed 2016 coup.

Turkey also wants assurances that arms restrictions imposed by the two countries over Turkey’s 2019 military incursion into northern Syria will be removed.

“I will not make any promises, but I can assure you that we are working actively to ensure progress because the application of Finland and Sweden to join NATO, they are historic,” Stoltenberg said.

Andersson said Sweden’s stance toward the PKK is “crystal clear” and that her country considers the organization as a terror group. She added that Sweden’s anti-terror legislation is undergoing its most comprehensive overhaul in 30 years.

“Moreover, constitutional amendments are being prepared, which would help pave the way for criminalization or participation in terrorist organizations,” she said.

NATO released new defense spending figures showing that U.S. allies in Europe as well as Canada have increased defense spending for an eighth consecutive year.

“By the end of the year, they will have invested well over 350 billion US dollars extra since we agreed our defense investment pledge in 2014,” Stoltenberg said.

NATO countries slashed their military budgets in the 1990s following the end of the Cold War, but upped spending when Russia annexed Ukraine’s Crimean Peninsula in 2014. In that year, NATO allies also pledged to reach a defense budget target of 2% of their gross domestic product by 2024.

“Nine allies now reach – or exceed – the 2 percent target. Nineteen allies have clear plans to reach it by 2024,” Stoltenberg said. “Two percent is increasingly considered a floor, not a ceiling. We will also agree to invest more together in NATO.”

Jan M. Olsen in Copenhagen contributed to this report.