Boris Johnson has told the Irish premier that “significant changes” are still needed with the controversial Northern Ireland protocol – after the taoiseach said there is an increasing view that it is working. The prime minister met taoiseach Micheál Martin in London where the pair discussed Ukraine and the protocol before watching Ireland beat England in the Six Nations at Twickenham. Johnson told Martin that he hopes the “same spirit of cooperation” the UK and EU have shared during the Ukraine crisis can be applied to Brexit discussions. A Downing Street spokesperson said: “The prime minister reiterated the need to make significant changes to the Northern Ireland protocol in order to protect peace and stability in Northern Ireland and safeguard the Belfast (Good Friday) Agreement in all its dimensions. “He said that while greater ambition and flexibility was needed from the EU in the negotiations, it was his hope that the same spirit of cooperation that had characterised the UK/EU relationship in respect of Ukraine could also be applied to resolving the issues with the protocol.” The protocol has created new economic barriers to trade between Northern Ireland and the rest of the UK. Agreed by the UK and EU to ensure no hardening of the Irish land border post-Brexit, it has instead moved regulatory and customs checks to the Irish Sea, with Northern Ireland remaining in the EU single market for goods. The region also applies the EU customs code at its ports. Unionists claim the arrangements have undermined the sovereignty of the UK and have demanded the UK triggers the protocol’s article 16 mechanism to suspend its trading provisions. Democratic Unionist party (DUP) leader Sir Jeffrey Donaldson said on Friday he will not go back into the Stormont executive until the matter of the protocol is dealt with. Earlier on Saturday, Martin said everyone he has met in Northern Ireland wants continued access to the EU single market. Martin was asked what the Irish government’s communication channels were like with the DUP and how likely it is that the issue of the Northern Ireland protocol will be resolved by the time of upcoming elections. Speaking to reporters at the embassy of Ireland in London, Martin said the Irish government has good channels of communication with all parties in Northern Ireland. He said: “What’s very interesting from our perspective though is that what’s increasing and growing is a view within Northern Ireland, particularly in Northern Ireland business and industry, that the protocol is working in terms of inward investment into Northern Ireland, and in terms of access to the EU single market. “So anybody I’ve met in Northern Ireland, all want to continue access to the EU single market. It’s a good basic principle to start off on. “And my view, given the improved relationship between the UK and the EU as a result of the partnership on Ukraine, I would like to think that in the fullness of time we will be able to resolve this issue. “But we’ll take it step by step. And there’s a channel there between the European Union and the United Kingdom that’s ongoing and we’re going to take this step by step.” Donaldson was applauded at Crossgar Orange Hall on Friday night as he said his party would not re-enter the Stormont executive until the government acts to “protect Northern Ireland within the United Kingdom”. Paul Givan resigned as first minister earlier this year as part of the DUP’s action against the protocol in a move which also removed deputy first minister Michelle O’Neill from the joint office. Johnson and Martin also agreed on “further sanctions to target the Putin regime” after their bilateral meeting, Downing Street said. A No 10 spokesperson said that they “agreed on the vital importance of continued unity in the face of Russian aggression”, which included humanitarian relief, defensive military support to the Ukrainian government and additional sanctions on Russia. The leaders discussed their “deep concern” about the “intensification of hostilities” near the Ukrainian capital Kyiv and condemned the attacks by Russian forces on civilians. The prime minister said this was a “critical moment” for Ukraine, as well as for wider European and international security when he joined the taoiseach for talks. A spokesperson for the taoiseach’s office said the pair discussed “the brutal Russian invasion of Ukraine and the profound global security, economic and humanitarian consequences”. They welcomed the “close collaboration” between the EU, UK and other partners to hold Russia to account and to address the humanitarian needs of the Ukrainian people, the spokesperson said. Earlier, the Ministry of Defence said fighting to the north-west of Kyiv continued, with the bulk of Russian ground forces about 15 miles from its centre. Last month, the EU, US and allies including the UK agreed to cut off a number of Russian banks from the main international payment system, Swift. The EU announced that the assets of Russia’s central bank were also frozen in addition to a crackdown on so-called “golden passports” that allow wealthy Russians connected to Vladimir Putin’s government to become citizens of a country.