The threat from Russia highlights the need to plug the gaps in the UK's defence budget, a Northern Ireland MP has warned.
Nigel Dodds' comments came as the Republic of Ireland became the 24th country to join the UK in diplomatic action against the Kremlin in response to the nerve agent attack in Salisbury.
Russian ex-spy Sergei Skripal and his daughter Yulia were poisoned on March 4.
Investigators say a military-grade nerve agent was used, but Russia has denied involvement.
After raising the issue during Foreign Office Questions yesterday, Mr Dodds, the DUP MP for North Belfast, said the Nato commitment of spending 2% of GDP on defence was vital.
He said: "The threats faced by our nation are changing and we must ensure the necessary resources are in place to meet those threats.
"While the Government stance has been exemplary, this must be followed through in all areas."
His comments came as Theresa May hailed the "unprecedented series of expulsions" of Russian diplomats across the globe in the wake of the Salisbury attack.
The Prime Minister insisted the move sent a strong message to Moscow that it cannot ignore international law.
With Downing Street saying that more than 115 Russian diplomats had been ordered home by friends and allies, Dublin added one more to the list.
Mrs May's spokesman said the PM told the Cabinet the move against Russia was "an unprecedented series of expulsions that has demonstrated to the Kremlin that we will not tolerate their attempts to flout international law, undermine our values or threaten our security".
The Prime Minister added: "It is also important to note that our partners are not only taking these measures out of solidarity with the UK, but also because they recognise the threat that these Russian networks pose to the security of their own countries and the pattern of Russian aggression which has affected us all." Yesterday Taoiseach Leo Varadkar said that Ireland was not one bit neutral when it came to assassination bids and chemical attacks as he justified the decision to expel a Russian diplomat.
Mr Varadkar rejected claims from Sinn Fein that the move against Moscow undermined Ireland's long-standing military neutrality.
Sinn Fein leader Mary Lou McDonald said Mr Varadkar was taking the decision based on the intelligence assessment of the UK.
"Essentially Taoiseach you are asking us to trust Boris Johnson (UK Foreign Secretary) and dare I say it, this might not be the wisest course of action," she told the Taoiseach during exchanges in the Dail.
Mr Varadkar said the expulsion of the Russian diplomat was a show of solidarity with the UK.
He insisted Ireland had "no quarrel with the Russian people".
The Taoiseach noted that other neutral countries, such as Sweden and Finland, had also expelled diplomats in response to the Salisbury incident.
"Ireland is a neutral country, we do not join military alliances, we will not be joining Nato, we will not be part of a European army," he said.
"However, when it comes to terrorism, assassinations and the use of chemical weapons and cyber terrorism we are not neutral, one bit."
Earlier Irish Foreign Minister Simon Coveney described the Salisbury attack as an affront to international law and order.
سایت تابناک از انتشار نظرات حاوی توهین و افترا و نوشته شده با حروف لاتین (فینگیلیش) معذور است.