NATO Secretary General Jens Stoltenberg on Thursday said he expected members to agree on a new investment pledge to spend 2% of their gross domestic product on defence at the alliance's summit in Vilnius, Lithuania, in July.
NATO countries need to "commit more", Stoltenberg told a joint press conference with Portuguese Prime Minister Antonio Costa in Lisbon.
"I welcome the recent increase in Portugal's defence spending, but all our allies need to do more," he added.
According to estimates in the NATO secretary-general's annual report released in March, Portugal spent 1.38% of GDP on defence in 2022, an increase for the prior year, but still below the target of 2% of GDP outlined by NATO.
For this year, the Portuguese government plans to increase spending to 1.66% - a goal that was initially set for 2024 - and reach 2% by the end of the decade, Defence Minister Helena Carreiras said in February.
Meanwhile, Costa said that as a founding country of NATO, Portugal "remains faithful to the values it has assumed".
The NATO chief has repeatedly urged allies to speed up increases in defence spending as the world had "become more dangerous" following Russia's invasion of Ukraine last year.
Seven of the alliance's 30 countries met the current 2% of GDP goal in 2022 - one fewer than in 2021, before the war in Ukraine - according to the secretary-general's report.
Stoltenberg said that at the Vilnius summit on July 11-12, the alliance would send a "strong signal of support" for Ukraine.
"I expect our allies will agree a multi-year assistance program to enable Ukraine to transition from the Soviet era to NATO doctrines, equipment and training and achieve interoperability with NATO allies," he added.
(Reporting by Sergio Goncalves; Writing by David Latona; Editing by Alex Richardson and Alistair Bell)
