Irish Taoiseach Leo Varadkar said he was open to either a short or long extension to Article 50, as he arrived at the EU summit in Brussels.
Mr Varadkar is meeting other EU leaders for a crunch summit with Theresa May who is asking for a delay to Brexit.
European Council president Donald Tusk has recommended that leaders of the remaining 27 EU countries approve an extension of up to a year, with a break clause allowing the UK to leave as soon as it ratifies its Withdrawal Agreement.
On Mrs May’s statement that she was not prepared to stay in the EU past June 30, he said: “Ultimately that decision lies with the House of Commons because the UK can leave before June 30, it can leave well before June 30 – it can leave in a matter of weeks.
“All that’s required is for the House of Commons to ratify the (Withdrawal) Agreement.
“I hope and trust the cross-party talks will allow that outcome to continue and allow us to do what we’re dying to do really, which is to get busy negotiating a new future relationship between the UK and the EU, one that is a very strong economic and very strong security partnership.”
He said he is confident an extension will be agreed at the summit, however, he said what remains open is how long the extension will run on and what the conditions will be.
Mr Varadkar, who is in Brussels with Ireland’s Minister for European Affairs Helen McEntee, added: “I think the vast majority of people here at the European Union appreciate that the UK is in a difficult position.
“The UK doesn’t want to leave without a deal, but at the moment it doesn’t want to vote for the deal and maybe half the population doesn’t want to leave at all.
“I think the general consensus here will be to give the UK a little bit more time for the cross-party talks that are happening to conclude and we can review the situation in a few months’ time.”
Mr Varadkar added he hoped the UK would join the EU in a customs union.
He said: “One thing I would like to see considered and which is under consideration is the possibility of a customs union being formed between the UK and EU.
“Ultimately the EU is the biggest trading bloc in the world, we trade more than China, we’ve a bigger population than the US, and in a world of big blocs it’s in the interests of the UK to be part of one of those blocs.
“It’s also in our interest to have the UK to be in our bloc and I think we would be generous in understanding that the UK couldn’t be a silent partner and would have to have a say in decisions being made.”