He linked the expulsion to a recent comment by the US secretary of state.
Foreign Minister Jose Manuel Garcia-Margallo said US Secretary of State Hillary Clinton also offered support.
It comes a day after US Secretary of State John Kerry landed in Afghanistan.
But US Secretary of State Colin Powell referred to it during his tour of the Mid-east.
The US Secretary of State met with Naomi Long during the event and offered her support.
Former US Secretary of State Hillary Clinton has announced her support for gay marriage.
The violence comes amid the first overseas trip by new US Secretary of State John Kerry.
The Iranians acted as US Secretary of State Condoleezza Rice was en route to the region.
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However, condemnation from the US secretary of state will carry more weight, our correspondent adds.
BBC: Azeri-Armenian clashes 'may escalate' - Hillary Clinton
On Monday, US Secretary of State Hillary Clinton said she was "concerned" and appealed for their safe return.
Ms Abedin, a longtime aide of former US Secretary of State Hillary Clinton, has said she has forgiven him.
Mr Straw also said he would be talking to US Secretary of State Colin Powell and European Union officials.
Later US Secretary of State John Kerry said there were "real concerns about the direction Egypt is moving in".
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An independent commission was set up to investigate the issue, chaired by future US Secretary of State Warren Christopher.
The US, meanwhile, has called for calm, with US Secretary of State Hillary Clinton urging "cooler heads to prevail".
BBC: China's central bank governor to skip key meeting in Japan
On Thursday, US Secretary of State Madeleine Albright renewed an offer to talk directly to Iran about US concerns with Iranian policies.
It's even more embarrassing on the eve of a visit by the outgoing US Secretary of State Hillary Clinton.
The US Secretary of State Colin Powell has been forced to pull out.
She was addressing a media briefing after US Secretary of State Hillary Clinton warned the deal could invoke US sanctions.
New US Secretary of State John Kerry has been holding talks with his Turkish counterpart on the conflict in Syria.
However, she and Mrs Clinton, as US secretary of state, have had to work closely together in the Obama administration.
Russian Foreign Minister Sergei Lavrov and US Secretary of State Hillary Clinton exchanged ratification documents at a conference in Munich.
Libyan leader Muammar Gaddafi should stop issuing threats against Europeans and resign instead, US Secretary of State Hillary Clinton says.
Beginning in the first Bush administration, Arabists like former US secretary of state James Baker began co-opting the realist label.
Last week, US Secretary of State John Kerry said thousands of Hezbollah fighters were contributing significantly to the violence in Syria.
Speaking in London on Monday, new US Secretary of State John Kerry said time for a diplomatic solution was running short.
Even so, US Secretary of State Hillary Clinton said the Iranian government should bear responsibility for what was happening inside Iran.
The US secretary of state dismissed concerns that Pakistan could be destabilised by its government's support for the US anti-terrorism campaign.
The report, which was unveiled by US Secretary of State Madeleine Albright, surveyed the state of religious tolerance in 194 countries.
Former US Secretary of State Henry Kissinger has warned that a crisis involving a nuclear Iran is in the "foreseeable future".
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